merge changes for 5.1.7-release

.hgtags

autobuild.xml

doc/contributions.txt

indra/llcommon/indra_constants.h

indra/llcommon/llcoros.cpp

indra/llcommon/llcoros.h

indra/llcommon/llerror.cpp

indra/llcorehttp/_httpservice.cpp

indra/llrender/llvertexbuffer.cpp

indra/llui/llscrolllistctrl.cpp

indra/newview/CMakeLists.txt

indra/newview/VIEWER_VERSION.txt

indra/newview/app_settings/settings.xml

indra/newview/llagentcamera.cpp

indra/newview/llagentcamera.h

indra/newview/llappviewer.cpp

indra/newview/llchathistory.cpp

indra/newview/lldirpicker.cpp

indra/newview/lldirpicker.h

indra/newview/lldrawpoolalpha.cpp