Web server performance optimization: Replaced the code which read the whole
file into a byte array with the more efficient http.ServeContent function.
Added support items of type 'presentation'.
Added deck.js to the default theme for displaying items of the type 'presentation' (see: http://imakewebthings.com/deck.js/)
Presentation style update: Adapted the presentation navigation style so that the go-to-page control is hidden when the screen is too smal to display it.
Added a keyboard shortcut for the page-jumper 'g'
Removed the converter file 'presentation.go'. This has been checked in by accident
Added highlight.js for syntax highlighting (see: https://github.com/isagalaev/highlight.js)
Merge with highlight-js branch
Removed the print styles from the deck-js css because everything is already defined in the default print style