utils/pylit should contain explicit GPL2 LICENSE file

[Jack Hale]

DOLFIN is LGPL v3, pylit although not linked or imported by DOLFIN, and therefore not an issue to include, is GPL v2. We should include the LICENSE file in the pylit folder to make this explicitly clear.

[Prof Garth Wells]

@jackhale Could you do this before the release?

[Jack Hale]

Added GPLv2 LICENSE file for pylit. Fix issue #708.

→ <<cset 30b838ce9e61>>