run.py fails if tinycc isn't built (windows)

[pkienzle]

sasview 4.3 developer windows

run.py fails on windows if tinycc is not built.

If tinycc does not import and the repo does not exist, then tell the user to pip install it or download the repo.

If repo exists but the build directory does not, then issue the build command in the tinycc repo.

If it still doesn't import, then remove "—compiler=tinycc" from the command line and hope the user has MSVC installed or mingw32 install and distutils configured.