Add CET style flags and support files

Check for compiler support of default CET "VIGILANT" flags and Werror,
adding these to CMAKE_CXX_FLAGS if the compiler can use them. Though
basic, this should reproduce the basic CET policy. These settings
could be promoted to the "UPS/CMake" layer where the ups driver/cache
would set CXXFLAGS or CMAKE_CXX_FLAGS when configuring.

Upgrade to CMake 2.8.8 and use CMakePackageConfigHelpers to generate
CMake config mode support files for use with find_package. At present,
only support setting include paths and variables for listing
compiler/version/stdlib details. More work is needed here to also
list the dependency on Boost, if it exists.