Fix verson detection and validation of KSP gamedir
Merge pull request #142 from ROMB/fix_directory_check

Fix verson detection and validation of KSP gamedir
Test framework organisation overhaul.

- CKANTests and NetKAN are root notes.
- Test classes are named after the code they exercise.
- Directory structure changed to reflect this.
- Test data now in `TestData.cs` for ease of re-use.

For #90
Added tests for IsKspDir() and test data.

Flipped IsKspDir() to internal so we can test it.

Three new data directories:

- `KSP/KSP-0.25` - A "good" install of KSP 0.25
- `KSP/bad-ksp` - A directory with no version info
- `KSP/missing-gamedata` - A 0.25 install with no GameData dir.

For #90
Populated GameData in test dir to make git happy.

Git doesn't really grok empty directories.

For #90.
Merge branch '90_test_ksp' into 125_fixups

NB: KSP.DetectVersion changed to *static*, as it uses no object data,
and this is how it's used in master.

* 90_test_ksp:
  Populated GameData in test dir to make git happy.
  Added tests for IsKspDir() and test data.
  Test framework organisation overhaul.
  Fix verson detection and validation of KSP gamedir

Conflicts:
	CKAN/CKAN/KSP.cs
	CKAN/Tests/Test.cs