This commit updates pandas and fixes dependencies.

Added version 0.18.0.
Added 'bin/f2py' to ignore so that activation works.

Removed unneccessary dependencies on
- libdrm
- libpciaccess
- llvm
- mesa

Added recommended dependencies from the pandas project site.
http://pandas.pydata.org/pandas-docs/stable/install.html
- py-numexpr
- py-bottleneck

The py-bottleneck is a new package that is also in this branch.

Removed optional dependencies
- py-scipy
- py-matplotlib

While those are most likely desired to be in the same python stack as
pandas they are not required by pandas.