Adds test for Inline::MakeMaker

These tests check that the two example modules included with Inline can
be can be run through the make/install process successfully.
Updated Inline::MakeMaker test to remove minor issues.

The test is now using IPC::Cmd and Test::More.
Modified system command strings to array refs in test.
Merge pull request #41 from neomorphic/devel

Adds a test to make sure Inline::MakeMaker is only using .pm files.