Added PYTHON_EXECUTABLE CMake option to trilinos.package.
Added CMake options for PYTHON_EXECUTABLE, PYTHON_INCLUDE_DIR and PYTHON_LIBRARY as found in dolfin.package.
Merged in poconbhui/dorsal/trilinos-python-executable-fix (pull request #5)

Added PYTHON_EXECUTABLE CMake option to trilinos.package.
Merged in poconbhui/dorsal/vtk-python-fix (pull request #7)

Added CMake options for PYTHON_EXECUTABLE, PYTHON_INCLUDE_DIR and PYTHON_LIBRARY as found in dolfin.package.