Change HttpOptions::ptr_t to be shared_ptr<> rather than intrusive.

indra/llcorehttp/_httpoprequest.cpp

indra/llcorehttp/_httpoprequest.h

indra/llcorehttp/examples/http_texture_load.cpp

indra/llcorehttp/httpheaders.h

indra/llcorehttp/httpoptions.cpp

indra/llcorehttp/httpoptions.h

indra/llcorehttp/httprequest.cpp

indra/llcorehttp/httprequest.h

indra/llcrashlogger/llcrashlogger.cpp

indra/llmessage/llcorehttputil.cpp

indra/llmessage/llcorehttputil.h

indra/newview/llinventorymodel.cpp

indra/newview/llinventorymodel.h

indra/newview/llmaterialmgr.cpp

indra/newview/llmeshrepository.cpp

indra/newview/llmeshrepository.h

indra/newview/lltexturefetch.cpp

indra/newview/lltexturefetch.h

indra/newview/llxmlrpctransaction.cpp