Removing tbb pipeline patch

Also makes TBB look for a system install, rather than automatically download.
And closes #99
:bug: Incorrect call to cmake when copying core.py
Simplifying how files are copied
Armadillo is passed MKL libraries

There were issues with passing lists to the script of cached variables which
prevented the blas libraries from being found
Updating TBB version
Merge branch 'rsdt/tbb_patchless' of github.com:bempp/bempp into rsdt/tbb_patchless
Bumping Trilinos to 11.6.2
python interface code to throw same exception as c++ code
Avoid tests trying to catch std::runtime_error

Apparently, libc++ and stdlibc++ are ABI compatible when it comes to most
execptions. Except for (AFAIK) std::runtime_error. And somehow both libraries
are pulled in when compiling on some Macs. I have not quite figured where and
why. In any case, this makes some test fail.

This commit is a workaround for #105
Merge branch 'rsdt/tbb_patchless' into rsdt/new_build