Fix test_llvmswitch to be valid C++11 code. Using an unsigned type would cause an error: case value evaluates to 4294967281, which cannot be narrowed to type 'int' [-Wc++11-narrowing] when compiled as C++11.
Add a unit test that checks that all platforms are building C++03 code by default.
Compile with -std=c++03 consistently on all platforms. By default, Clang 3.2 inconsistently uses C++11 for Windows and C++03 for Linux if user did not specify -std= on the command line. Fixes other.test_embind and *.test_llvmswitch. Add unit tests that confirm that .cpp files are compiled with C++03 std by default.
Add a unit test that checks that user is able to specify a custom -std= flag on the command line.
In test runner, don't pass -std=c++03 when building .c files.
Merge pull request #825 from juj/std

Std