Add heat conduction process.

Wrote some more docu

Move some data from Process to Timeloop

Dmitri Naumov authored 8 years ago and Christoph Lehmann committed 8 years ago

Only const version for now, which is sufficient.

unsigned int in Gauss integration methods

Changing the initialization order in the local assemblers
is required.

Creating integration method object for every assembly
is not cheap because of the std::pow call. Since the
method does not change, it can be stored once per
assembler.

Docu part 3