Updated for external links
Fixed link text, added link type glyphs
Basic pinch-to-zoom support
perf work for phone and arm
Improvements to image scaling
Merge Z:\
added serializable, phone tends to try to serialize more stuff then W8 does, so these seem to need the ability
reduce memory footprint of gif renderer
Reduced memory allocation by keeping around the workbuffers and using them between all of the markdown renders
tweaked comment loader to optimize for phone and arm