Updating linux build to gcc4.6

BuildParams

autobuild.xml

indra/cmake/LLCommon.cmake

indra/cmake/LLXML.cmake

indra/cmake/UI.cmake

indra/integration_tests/llimage_libtest/CMakeLists.txt

indra/integration_tests/llui_libtest/CMakeLists.txt

indra/linux_crash_logger/CMakeLists.txt

indra/linux_updater/CMakeLists.txt

indra/linux_updater/linux_updater.cpp

indra/llappearance/llavatarappearance.cpp

indra/llcharacter/CMakeLists.txt

indra/llcommon/llsdserialize.cpp

indra/llcommon/tests/bitpack_test.cpp

indra/llcommon/tests/llinstancetracker_test.cpp

indra/llcommon/tests/reflection_test.cpp

indra/llcrashlogger/CMakeLists.txt

indra/llinventory/CMakeLists.txt

indra/llmath/llvolume.cpp

indra/llmessage/llhttpassetstorage.cpp