fully integrated `libuv` networking features, more examples

• added methods/functions:
  net_operation, dns_address, dns_name, dns_record, listener_task
net_listen, net_client, net_server, net_stop, net_accept, net_connect, net_bind
net_read, net_write, net_close, net_peer, net_request, net_response
  These functions to methods behavior depends on uri scheme, and either a libuv object or stream/fd/socket resource passed in.
• added more upstream libuv network tests and examples.
• added stateless_task function to cause tasks/coroutines not to keep task completion state or data.
• added NetworkAssistant class for handling network message processing, works similar to PSR-7
• code clean up, corrections
• added an PHP version of Python and NodeJS sync/async examples from https://medium.com/@interfacer/intro-to-async-concurrency-in-python-and-node-js-69315b1e3e36
• Refactoring for examples not working as expected
• insure progressTask only execute if actual data is returned
• added two utility functions similar to NodeJS, Python usage as random_uniform and timer_for
• update readme to show php version same as nodejs and python

1.9.2: Corrections for implementing proper `libuv` network related features.

- rework `isUvActive()` for only Linux detection, and control whether native PHP `network` events are checked for and executed first

1.9.1

• reduced required PHP version to 7.1 - using proc_open for subprocess operation no longer necessary, so keeping up with symfony/process package not needed.
• reorder to have PHP native events to run first, before libuv events, the other way was causing timing and various issues.
• added file_delete to recursively delete in thread/subprocess.
• added methods/routines and examples to have libuv handle file changes monitoring on the file system.
• use libuv uv_timer feature as default for sleep_for and wait_for task execution timing control, add test for native check.
• update readme to a new paradigm, and docblock corrections/updates.
• have Coroutine setup method control libuv overall and other class state.
• added method to retrieve the Task object instance from task id.
• bug fixes, the channel ipc progress feature wasn't working correctly when other tasks running, some workaround fixes for now.
• update test/example to match required BC version.
• rework how gather handle subprocess tasks.
• improve coroutine execute method when being re-entering from gather.

BC - updates, class renaming, added `subprocess` progress ipc interaction, and better signal handling

Next version will began phasing in Linux libuv network stream/fd/socket feature, Widows support is broken will continue to use stream_select for the same feature.

• uv_run() now executing on all yield iterations
• added signal and ipc progress examples
• rework shutdown, and various bug fixes found when adding examples
• added $tasktype to addProcess method, subprocess calls need to be force run if upon entering gather method the process task not running, signal subprocess tasks handling differently
• update required, readme docs and docblock comments
• update memory handling, add close methods to Parallel, and Task, have auto destruct, check for valid instance before stopping
• spawn_kill will also cancel and remove the task

`uv_spawn` process signal handling implemented

• add/test uv_spawn signal handling routines, added spawn_kill, spawn_signal, and signal_task
• update spawn_kill to cancel and remove the task
• update memory handling, added close methods to Parallel, and Task, and auto destruct
• update required, renamed methods for consistency

BC and general reworking for handling `uv_spawn` for child subprocess calling

This version onward will use uv_spawn and other features of libuv for subprocess execution, if not install the fallback will use previous system of proc_open.

• update namespaces
• update Parallel success, fail, and timeout call signature, added signal handling
• update Parallel to require Coroutine class at creation, increase concurrency
• update required and readme/docs references
• remove sub process default timeout
• moved constants/stubs to symplely/spawn
• Use Github Actions for all CI builds/tests

maintenance release before library change - `symplely/processor` to `symplely/spawn`

The next version will use symplely/spawn that uses uv_spawn of libuv for child subprocess management/execution.
The fallback will use same aspects of symplely/processor, if libuv not installed.

• update constants
• insure file operation writes/reads are unbuffered
• update/test file_sendfile for usage without libuv, update file operation headers for uri calls
• update required, fixed to symplely/processor v1.4.3 for subprocess manager

Code cleanup, general fixes for file operations

• added directly have file_meta return the size, content length
• docblock corrections
• add internal functions to properly catch returns within tasks or any function/method
• insure open handle wrapper types
• various file operation updates/tests
• bug fixed file_contents, and added file_sendfile

1.7.2: add option to pass context to `file_uri`, various bug fixes found whe…

…n adding `fileUri.php` example

corrections/bug fix, `ioWaiting` was not checking for pending file operations, and on Linux not writing correctly

1.7.1

various updates, bug fix for Linux file operation not writing correctly