Ignore @import when prefixing custom CSS, re-ordered theme stylesheet inclusion

fixes GH-199
Show the font of the currently selected text GH-232
New textboxes have the state of the last edited textbox. GH-233
Added the XML mode so html input will get syntax highlighting
Enabled syntax highlighting for the CSS editor
Plumbing for custom color classes
Various plumbing tweaks / fixes
Renders the customBgStylesheet based on the user's chosen colors
Renders the custom backgrounds into the presentations
Explicitly sets the color on spectrum when closing the color chooser modal

This resolves an issue where the most recently selected colors were not present.
Update README.md
locale file for Russian language
Merge pull request #237 from kuroineko/master

locale file for Russian language
Updated the flat theme
jsdoc
Fixed alignment, removed log statement
Merge pull request #239 from tantaman/custom-bgs

Custom background colors