Merge branch 'sam_osxbuild' into sam_gtest
Added gtest to external directory.
Updated the Makefile so that googletest would have hope of compiling.  (It fails due to compiler warnings.)
Fixed a whole bunch of unittest comparison assertion signedness to play nice with OS X.
Made perfmon_tests.cc compile on Linux, by including <cmath>.
Updated .gitignore to ignore gtest-1.6.0 output.
Removed the verbosity of the gtest-1.6.0 Makefile.
Merge branch 'sam_osxbuild' into sam_gtest
Fixed some LT assertions of rpc_connectivity.cc that had been reversed.
Made the gtest build use $(MAKE), re-enabled default building of unit tests.
Merge branch 'next' into sam_gtest
Merge branch 'next' into sam_gtest