parameter tree parser: do not try to access the first character of empty strings

funnily enough, this usually worked (i.e. it returned some garbage
which was not recognized by the switch statement that followed), and
was not detected by valgrind (on my machine at least, I suppose this
was because the address to which the string pointed was still a valid
memory location created by some previous user). The libstdc++ debug
mode (-D_GLIBCXX_DEBUG=1 -D_GLIBCXX_DEBUG_PEDANTIC=1) did find it
though...
Reduce number of warnings.

nullptr-test.cc: Move semicolon to own line to prevent
Clang warning.
typetraitstest.cc: Exclude use of deprecated types
PointeeType and ReferredType with
DISABLE_DEPRECATED_METHOD_CHECKS defined.
paralleltest added
paralleltest added
remoteindices: fixed formattation
parallelparadigm created
parallelparadigm created
parallelparadigm: removed useless classes
parallelparadigm: clean up
remoteindices: clenaup
remoteindices: changed template arguments
remoteindices: constructor changed
parallelparadigm: some templates fixed
parallelparadigm: templates fixed
remoteindices: rebuild not working
fixed buildremote and cleanup of remoteindices
remoteindices: communicator removed
parallelparadigm: MPI support completed
remoteindices: cleanup
parallelparadigm.hh: renamed mpiparalleparadigm.hh