PyAnalysis Fix, 1.0 branch (2018.01.30.)

Modified PyAnalysis to use a single "build directory" while building all of the python modules. Since it turns out that easy-install wants to keep updating the same (easy-install.pth) file, which describes what modules are installed in the current directory. If we don't allow the same file to be filled with info about all of the modules, they don't end up being accessible after installation.

@ksuruliz, this was the issue breaking the NumPy installation in the latest releases. In the past I was only installing NumPy "this way". But recently I added Pip (and Wheel) as well. And these broke the NumPy installation as it turns out...