Fixed failing parse_c unit tests.

[jtpaasch]

Tests passing now (so fixing #119). The trick is to ensure that Project.create is not called before Bap_main.init ().

Apart from a few stylistic changes, the important changes I made to ensure that the parse_c unit tests pass are these:

• Do not create a project at the top level of the bap-vibes/tests/unit/helpers.ml module.
• Do not create orig_proj and patch_proj at the top level of the bap-vibes/tests/unit/test_verifier.ml unit tests. Instead, create those projects inside each unit test that needs them.

[codyroux]

Not exactly how I would have done it (I would have just added a unit argument to delay evaluation) but this works just as well, and looks great.

Approved.