Merge skinning-14 to viewer-2, including refactoring many floaters to register...

Merge skinning-14 to viewer-2, including refactoring many floaters to register them with LLFloaterReg, support for introspection of ParamBlock based UI widgets to dump XML schema, splitting llfolderview.cpp into three separate files to unravel dependencies and skeleton for for LLListView widget.  Resolved conflicts in these files:
lldraghandle.h, lluictrl.h, llchiclet.cpp, llfolderview.h/cpp, lliinventorybridge.cpp, llpanelpicks.cpp, llviewermenu.cpp, floater_mute.xml, floater_preferences.xml, notifications.xml, panel_preferences_audio.xml, panel_preferences_graphics1.xml, panel_region_general.xml
svn merge -r124961:126284 svn+ssh://svn.lindenlab.com/svn/linden/branches/skinning/skinning-14