Step-34:

Step-34:
Rewrote almost all formulas in a consistent manner (almost all signs
were wrong). Removed all references to Galerkin BEM. Now it is a purely
collocation BEM, that uses advanced integration rules just added
to deal.II. Once MappingQ of arbitrary order are implemented, this should allow
for very advanced BEM solutions, with very few unknowns.
Added a couple of pictures of solutions, and the parameter file at the end.
Still missing is a completion of Wolfgang addition to the introduction.

git-svn-id: https://svn.dealii.org/trunk@18552 0785d39b-7218-0410-832d-ea1e28bc413d