SH-3604 WIP - added base outfit link creation to retryable copy/link operations. Resolves race condition with cof version and server texture bakes

Fix for building on case-sensitive mac filesystems.  Fix to remove unwind spam warnings while linking on xcode 4.5.2 builds

Removed duplicated block of code in LLAddBuildTest.cmake. Added comment to point to duplicated code. Replaced hard-coded tcmalloc link option with variable that is created in GooglePerfTools.cmake.

Restored test_llcorehttp_peer.py, hopefully breaking the 'hg copy' link that was causing changesets intended for its copy parent to be applied to the child file.

Deleting test_llcorehttp_peer.py because it has been corrupted by changes to test_llsdmessage_peer.py, which it was copied from. The file will be recreated using an unchanged file.

On Linux now use the default system python instead of defaulting to python2.5. This was a holdover from when on linden systems 2.5 was newer than the default, instead of older.

SH-3604 FIX - switched link creation in updateCOF() to use retry path, better stats reporting, fixed failure logic

* Removed no longer used unpack_bufsize from bitpack_test.cpp
* Added llviewertexture_stub.cpp to the newview tests directory to fix llworldmap_test.cpp and llworldmipmap_test.cpp linker errors.