config: first draft (using boost::program_options)

This supports registering command line arguments for different modules
of PFASST++ separately via special static functions.

This introduces dependency on boost::program_options.

see #45
config: registering config options for SDC and AdVec

see #45
config: usage example for command line parameters

Exetuables will need to enable command line options manually.
config: introducing single init function; add quadrature parameters
cmake / travis: fixing Travis and CMake compiler version detection
config: fix GCC build

somehow, GCC has trouble dealing with template specializations and
changes of the storage class in them
travis: fixing Boost ?
tests: 'fixing' Scalar highprec test

deactivated GCC on Travis due to linking problems
another try on fixing Travis
examples: fix van-der-Pol linking
Merge pull request #88 from torbjoernk/feature/param-parsing

Enabling Commandline Parameters