Schemes: Added support for CSS font-stacks

(integrated from trunk branch change b8c0945 by Nathan Rijksen <n.rijksen@gmail.com>)
Schemes: Updated the base16 schemes with CSS font stacks

(integrated from trunk branch change b855e6e by Nathan Rijksen <n.rijksen@gmail.com>)
Icons: Delete icon cache on upgrade/downgrade

(integrated from trunk branch change eab56ff by Nathan Rijksen <n.rijksen@gmail.com>)
Icons: Force prefs until bug #104645 has been fixed

(integrated from trunk branch change f5f3d08 by Nathan Rijksen <n.rijksen@gmail.com>)
Icons: Fix statusbar language icon size too big

(integrated from trunk branch change 82ecefe by Nathan Rijksen <n.rijksen@gmail.com>)
Icons: Updated html, JS, python and coffeescript icons

Improved sharpness and overhauled symbols

(integrated from trunk branch change e33e19a by Nathan Rijksen <n.rijksen@gmail.com>)
Commando: Fix: files failing to open on Windows

https://bugs.activestate.com/show_bug.cgi?id=104835

(integrated from trunk branch change 8c417ba by Nathan Rijksen <n.rijksen@gmail.com>)
Languages: Unmark XSLT as a primary language

(integrated from trunk branch change 135b6a0 by Nathan Rijksen <n.rijksen@gmail.com>)
Commando: Relative searches are now relative to the current file in the editor

(integrated from trunk branch change 85161e2 by Nathan Rijksen <n.rijksen@gmail.com>)
Icons: Add CoffeeScript icon to Conscript

(integrated from trunk branch change 1cd34fc by Nathan Rijksen <n.rijksen@gmail.com>)