Added some non-pst test files to check identification.
Added initial unit tests for detection and a test suite.

So a test suite runs all tests (hand for checking), and the detector
now runs through the test files and checks that:

  * Test pst files are identified as such
  * Non-pst text files aren't identified as pst

Adding non pst files to the nonpst test resource directory automatically
adds them to the test (likewise for pst files).
Merge branch 'master' of github.com:dmmd/OPF_Hack