MAINT-2980 Fix for mac cutting texture memory in half (now that we're cutting texture memory to default to 1/3rd of installed ram, pre-cutting is redundant).

MAINT-2980 Fix for AMD cards reporting system ram + vram for dedicated vram -- use WMI instead of DxDiag to get dedicated video memory.

MAINT-2980  Up texture memory slider cap to 4096MB.  Make "Texture Memory" default to 1/3rd of video memory.  Add description on debug setting and tooltip to explain why.

STORM-2035 - Invert the background color in script editors for highlighting sections. Since the background color can be changed by the user, this ensures distinctive highlighting

STORM-2036 - Fix trying to parse caps too early by adding a callback to check region caps when they haven't already been received

BUG-6425 - Init default keywords file during ctor so we have something to fallback on should caps or fetch fail

DRTVWR-354 : Rewrite Responders for Twitter and Flickr to conform to new LLHTTPClient interface. Fix merge error in Facebook connect as well

* Move file fetched callback to the singleton and handle all syntax id changes within the singleton
* Remove a fair number of bool checks and method relying more on callbacks to drive syntax changes.
* Don't pretty print the cache file to conserve space and to speed up xml to llsd parsing
* Clean up includes