Added llFloaterExperiencePicker, mainly for use by region owners.

indra/newview/CMakeLists.txt

indra/newview/llfloaterexperiencepicker.cpp

indra/newview/llfloaterexperiencepicker.h

indra/newview/llviewerfloaterreg.cpp

indra/newview/llviewerregion.cpp

...ewview/skins/default/xui/en/floater_experience_search.xml

indra/newview/skins/default/xui/en/menu_viewer.xml

...newview/skins/default/xui/en/panel_region_experiences.xml