Moved QT4 search to ThirdParty module.
Tidied up other parts of cardiac solver code.

Conflicts:
	library/LocalRegions/HexExp.cpp

Substitution of Riemann ExactSolver with Riemann ExactToroSolver. Modification of regression test accordingely.

Conflicts:
	solvers/CardiacEPSolver/EquationSystems/Monodomain.cpp

Tidied up 2D MultiplyByQuadratureMetric calls.

Removed code duplication in MultiplyByQuadratureMetric routine.

Fixed contour update offset when changing interpolation distance.

Corrected mistake with isentropic vortex exact solution.
Fixed issue where wrong number of points being used in boundary conditions.
Added ExactSolverToro to implement Toro's exact Riemann solver.
Corrected various Riemann solvers to enable correct 3D calculation.
Modifications to library, 3D parallel advection now working but needs testing.