vt build system calls checkpoint cmake macros

[nlslatt]

Describe the bug When an error occurs in find_package_local, cmake reports (correctly) that it was executing the version in checkpoint, not in vt, at least when checkpoint is dropped into vt's lib subdirectory.

To Reproduce Steps to reproduce the behavior:

1. Example/test/snippet of code that fails
2. Compiler, platform, libraries
3. Run command: number of processors, threading options, etc.
4. See error

Expected behavior A clear and concise description of what you expected to happen.

Screenshots If applicable, add screenshots to help explain your problem.

Platform (please complete the following information):

• Supercomputer or desktop [e.g., Trinity, Sierra)
• Compiler environment [e.g., clang-3.9, gcc8]
• Libraries [e.g., mpich-2, openmpi)
• Commit ID or release of VT [e.g., vt-1.0.0]

Additional context Add any other context about the problem here.

[nlslatt]

The link below describes some of the potential pitfalls of writing our own cmake function. We should probably plan some significant refactoring.

https://cmakedev.readthedocs.io/en/latest/cmake/writing_functions.html