BUG: missing dependency of dist.Python on actual python library

Because the same variable was for the SWIG target was used in both the
Python and R wrapper, a new alias variable needed to be created, which
include Python on the name.

Change-Id: I7f32e4a2b3dde0f04fc870027c6bd70c12cfb55a
Adding missing quotes around @s, and numpy not required

Having a space in the source name caused problems with the
installation due to unquoted @ substitutions.

If the python installation did not have numpy, a failing error would
be returned causing the build to appear to have failed. Now the
installation is just skip. So just a couple tests will fail.

Change-Id: Ia1bca43b0a642b0229f0079660e5be7292c3df6d
Merge topic 'SIMPLEITK-350_Include_stdint_VS9' into next

70616fa Adding missing quotes around @s, and numpy not required
21005ee BUG: missing dependency of dist.Python on actual python library