allow specifying the directory containing CMakeLists.txt
allow specifying the directory containing CMakeLists.txt

Summary:
Update `cmake_configure()`, `cmake_install()`, and `fb_github_cmake_install()`
to support specifying the directory where CMakeLists.txt is found, relative to
the directory where the build is being performed.  Previously these functions
where hardcoded to assume that CMakeLists.txt was always found at '..'

Reviewed By: snarkmaster

Differential Revision: D7540689

fbshipit-source-id: efd3d044345fadc0346e436c01d0a247e1b6fd70

facebook/bistro,facebook/bistro,facebook/bistro,facebook/bistro,facebook/bistro,facebook/bistro