Support neovim

[puremourning]

Fixes #29

• Remove bindeval: Instead, require a send function in the job/channel API, and marshal the arguments through global variables.
• Abstract terminal API
• Abstract job API

TODO:

• Fix SetUpCommandBuffer so that the output of the command actually appears in the buffer in neovim. Don't understand why this doesn't work
• Abstract channel api
• replace WinBar in code view ? Or just rely on mappings ? Maybe a help window ?
• replace winbar in output view with :VimspectorShowOutput <tab complete cetegory>
• find a way to make :Vimspector... commands discoverable ?
• add :VimspectorEval <tab complete expr> and :VimspectorWatch <tab complete expr>
• add :VimscpectorReset

Might decide nvim is "best effort" basis only. If not, will need to:

• add neovim jobs to CI (docker images, versions, yada yada)
• port the whole test framework to neovim
• write a lot more tests. there aren't enough tests to support 2 runtimes yet.

Known issues:

• can't set environment variables when starting jobs in neovim (only in neovim master)

But, here's vimspector "working" in neovim:

[puremourning]

This change is 

[lgtm-com]

This pull request introduces 1 alert and fixes 1 when merging a553b5f into 68c47ed - view on LGTM.com

new alerts:

• 1 for Syntax error

fixed alerts:

• 1 for Modification of parameter with default

[puremourning]

Reviewable status: 0 of 18 files reviewed, all discussions resolved

[puremourning]

Reviewed 16 of 18 files at r1, 2 of 2 files at r3, 1 of 1 files at r4.
Reviewable status: complete! all files reviewed, all discussions resolved

[puremourning]

Reviewed 1 of 1 files at r5.
Reviewable status: complete! all files reviewed, all discussions resolved

[puremourning]

Reviewable status: complete! all files reviewed, all discussions resolved

[srillia]

neovim open debug mode ，watcher can't write