Fix bug that would delete languages without reinstalling
Merge branch 'release/0.3.0'

* release/0.3.0: (25 commits)
  Bump version number
  A little extra documentation
  Update CHANGELOG and README for updates
  Add options page screenshot
  Properly migrate XML -> Markup
  Add new screenshots
  Actually fix line number display bug
  Fix bug with display on options screen
  Add line number enable/disable
  Beginning of option page
  Add "gistpen-{$post_slug}" to <pre> id for line linking
  Add line-highlighting with "highlight" in shortcode
  Move language class to code element where it belongs
  Add line numbers
  Views don't belong in assets...
  Set up migration for new language support and dropped language support
  Refactor content manipulation into helper class
  wheee whitespace
  Add version option when plugin is activated
  Initial switch to Prism
  ...

Conflicts:
	public/class-wp-gistpen.php
Merge branch 'refs/heads/develop'

* refs/heads/develop:
  Forgot to minify JavaScripts
Need to remove filters in the updater

Otherwise, we get escaped content saved to the DB
Filename smaller h2->3
Fix inhertiance in TinyMCE pop-up
Enqueue css only on edit screen
Merge branch 'develop' into release/0.4.0

* develop:
  Only add filter if errors isn't empty
Fix failing tests for content
Type checking

Is that what it's called? Object instance type checking?
Fix insert Gistpen dialog
Fix the insert Gistpen popup
Major refactoring

Query class now returns a WP_Gistpen_Post with an empty `files` property instead of an array with a blank file + refactoring around that change.
Bump version number
Update docs
Add icon and move screenshots
Merge branch 'release/0.4.0'

* release/0.4.0: (126 commits)
  Add icon and move screenshots
  Update docs
  Bump version number
  Major refactoring
  Fix the insert Gistpen popup
  Fix insert Gistpen dialog
  Type checking
  Fix failing tests for content
  Only add filter if errors isn't empty
  Enqueue css only on edit screen
  Fix inhertiance in TinyMCE pop-up
  Filename smaller h2->3
  Need to remove filters in the updater
  Whoops, mistake with errors
  Error checking on front end
  ALL THE ERROR CHECKING
  Clean up and test the saver
  Clean up updater
  Extra error check in language
  Refactor and add to AJAX tests
  ...
Merge tag '0.4.0' into develop

0.4.0

* tag '0.4.0':
  Add icon and move screenshots
  Update docs
  Bump version number
  Major refactoring
  Fix the insert Gistpen popup
  Fix insert Gistpen dialog
  Type checking
  Fix failing tests for content
  Enqueue css only on edit screen
  Fix inhertiance in TinyMCE pop-up
  Filename smaller h2->3
  Need to remove filters in the updater
  Fix bug that would delete languages without reinstalling