added Flag as value type
moved Batch to BatchBlock
renamed Choice to ChoiceBlock
made merging of parameters for ValueParams consistent (fillFrom and overwriteFrom are inverses of each other now)
made iteration over Multiple<T> type params easier
initial schema param blocks
changed ordering of template loading relative to constructor setting of params
moved a lot of constructor-set params to template files
reviewed by Leslie
EXT-2011 titles of IM sessions aren't aligned to center
EXT-3025 Pick's description overlaps picks name
also moved tool tip param default to tool_tip.xml
also made default param<const LLFontGL*> be SansSerif
reviewed by Leyla
Oz Linden