Fix rest of solvers, utilities and libraries, and add HashUtils to fix some issues with C++11 unordered data structures

Switch to a simple static member function to implement singletons, which is guaranteed to be thread-safe in C++11.

Add regression test, some verbose information and fix incorrect functionality in the Tester regex module.

Added support for input files to be located in a different directory to the test file.

Remove CHUD option since this is no longer provided in OS X.
Add a few comments to CMakeLists.

I've modified the Tester driver program to be configured by CMake. The
MPIEXEC program and its flag to specify the number of processes is now
given through CMake and a NEKTAR_TEST_FORCEMPIEXEC option added. If
the compiler has MPI_BUILTIN (as on Cray machines), then the minimum
necessary options that would have been set by FindMPI.cmake are set.

Generalised error calculation and output.
Linf now computes max value in solution, rather than zero, to be consistent
with L2 equivalent.

Added an initial test for Courtemanche.