Configure clang tidy to run with all targets

[Sqeaky]

Using something like this:

set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-style=file;-checks=*")

We can have clang tidy run with every target this could catch a few extra issues.

[Sqeaky]

Here is some code I was playing around with that should allow this, but the unit tests slowed to a crawl and will require more investigation:

if("${CMAKE_VERSION}" VERSION_GREATER "3.7.0")
    find_program(MEZZ_ClangTidy clang-tidy DOC "The clang-tidy executable the Jagati could use.")
    if(EXISTS "${MEZZ_ClangTidy}")
        message(STATUS "CMake is supports Clang Tidy and it was found.")
        set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-style=file;-checks=*") # this breaks the tests
    else(EXISTS "${MEZZ_ClangTidy}")
        message(STATUS "CMake is supports Clang Tidy but it is not installed.")
    endif(EXISTS "${MEZZ_ClangTidy}")
else("${CMAKE_VERSION}" VERSION_GREATER "3.7.0")
    message(STATUS "CMake is too old to support automatic use of Clang Tidy.")
endif("${CMAKE_VERSION}" VERSION_GREATER "3.7.0")