Test for C++11 range-based for support

Implement simple compile/run test of range-based for support. If test
passes, set CMake variable HAS_CXX11_RANGE_BASED_FOR. Document this
variable in the module, and link to FNAL cpp0x equivalent definition
in README.
Rename regex test to lib_regex

Match cpp test file name to variable set by test so that documentation
and calls of test function are in the same order.