changed ordering of template loading relative to constructor setting of params
moved a lot of constructor-set params to template files
reviewed by Leslie
Bug was caused by setting image overlay with arrows that have "transparent" color when arrows are not needed. When scrollist was disabled while refreshing, they somewhy were visible in black color.
- Now null image overlay is set when arrow shouldn't be visible.
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
Richard Linden