Adding tests for aca options

This is the first complete python module with mako.
Python headers are now handled independently. This is necessary since the
cython source files depend on the generated cython header files. So all mako
generation should happen before cython is called.

In order for cython to find generated and normal pxd files, the headers are all
installed within the bempp package. This goes some way towards #139.

Also goes some way towards #128.
bempp.options.Options wraps instance of AcaOptions

Rather than redeclaring variables. This is simpler and makes back and forth
between python and C easier.
Test for AcaOptions python -> c unnecessary

Since now an AcaOptions is actually owned by bempp.options.Options
Add parallelization options
Added most of bempp options

Goes through mako options.
Still needs some few hand tailored options.
Unified previous options into a single dictionary that describes the wrapper
implementations.