v0.4

Changelog:

Web Interface:

• The page to modify metadata of volumes has been added. If you have
  enough permission you should see a button with a pencil on the single-volume-view page.
• Added support for paginated results in search page.

CLI:

• added new command libreant-db insert-volume to insert a volume along with its attachments.
• added new command libreant-db attach to attach new files to an already existing volume.

Logs:

• changed default log level to INFO.
• all startup messages are now printed using loggers.
• using recent versions of gevent (>= 1.1b1) it is now possible to
  have a completely uniform log format.

Warning:

• Due to breaking changes introduced in new version of Elasticsearch (deprecation of _timestamp field),
  it is not possible to use libreant with version of Elasticsearch major or equal to 2.0.
  Probably in the next release we'll provide support for these versions.