Add grid manager panel back

indra/newview/CMakeLists.txt

indra/newview/alfloatergenerictext.cpp

indra/newview/alfloatergenerictext.h

indra/newview/llfloaterpreference.cpp

indra/newview/llfloaterpreference.h

indra/newview/llviewerfloaterreg.cpp

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

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

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

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

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