Fix x11grab detection for newer ffmpeg versions

Newer ffmpeg versions use libxcb for capture and not the old xlib
method.  In this case the --enable-x11grab option is not used and the
detection code fails.  We check the 'ffmpeg -devices' output for x11grab
to verify support instead.

FFS-063 Adding conversion tools

FFS-062 Fix wording for listing rec devices

* 'master' of github.com:cytopia/ffscreencast:
  Define the binary as actual binary for composer
  FAQ: Hide mouse on Linux/BSD
  FAQ: Alter default options via config file
  FAQ: Capture the mouse on OSX
  Adding info about how to create a gif
  Adding info about how to create a gif
  install guidelines

Define the binary as actual binary for composer

This change will make composer create a link to binary folder. For now installations are not useful because of that fact.

* 'master' of github.com:cytopia/ffscreencast:
  changed default extension

* feature/dependency-rewrite:
  CHANGELOG
  Markdown Linting
  Ruby gems