* Cleanup syntax highlighting styles
* Replace hardcoded color values with [base16](http://chriskempson.com/projects/base16/) Sass variables
* Harmonize padding between GFM code blocks and `{% highlight %}` code blocks
* Improve readability of line numbers
* Add longer code block example to test double digit line numbers
* Adjust code block colors for specific skins
* Remove Lunr trimmer & bring back colons
* Add Greek Stemmer
* Translate search_placeholder_text and results_found to Greek
* Minimize JSON data
* Truncate Words
* Move store variable into a new file
* Move Lunr files into a new folder
* Add defer to lunr scripts
* Add search_full_content switch
Code blocks with short line widths can cause `td.gutter` width to stretch, adding in undesired white space.
Declaring widths on the table's columns fixes#1437
Add `{% highlight linenos %}` examples to test and demo sites.
Make excerpts optional in header overlay
Some posts and some header images don't lend themselves well to
displaying the excerpt in the overlay. Make this optional by
introducting a new boolean variable:
`page.header.show_overlay_excerpt`
Set it to implicitly default to `true` so existing users are unaffected by
testing explicitly for "!= false".
This can be enabled globally for a site by changing the default to `false`
in the local _config.yml, or per page by specifying the value in front
matter.
Document show_overlay_excerpt variable
* Add show_overlay_excerpt variable to the Header Overlay field documentation table.
Close#1429
