First batch of auto_ptr to unique_ptr

Changed all in lib/assembly subdirectory.
Changed one test outside that directory.
Tests compile and run.
One auto_ptr is left. It comes from boost not recognizing unique_ptr. It will
be modified with another instance of the same problem in a single later commit.

One step towards #111
Moved almost all auto_ptr to unique_ptr

Goes towards #111
Changing auto_ptr to unique_ptr in non-c++ files

Meaning backup files(?) and python docstring files.
Boost::map_ptr members not overloaded for std::unique_ptr

Closes #111. See issue #112.
Removed warnings generated by -Wall

Deprecation and unknown pragma warnings are left.
There are still some warnings from SWIG.
:lipstick: simplify cmake file minimally
Last auto_ptr from test with new dune

Introduced in thread from #114
Remove warnings from compiling with NDEBUG

Mostly, some variables need not be declared when compiling in release mode.
These variables are only used in asserts.
Add checks in build system for unique_ptr and nullptr
Fix #124, cmake always instigates complete rebuild

The fake Fortran header file build/include/FC.h was being created every time
CMake ran. Adds guards to only create it if it does not exist.
This prevents from rebuilding after each call to CMake.
Merge pull request #123 from bempp/rsdt/pointers

Rsdt/pointers