Split test code from library and merge with test data

[GoogleCodeExporter]

In order to reduce the number of binary packages (Issue #83) it makes more sense to merge test cases with the test data. At the same time we still want test cases to be committed together with the code changes.

Therefore we will reorganise the layout of the repository to look something like this:

   /mdanalysis
              /package
              /tests

where package will contain the current trunk without MDAnalysis/tests and tests will contain MDAnalysis/tests together with the test data.

Because git is much better at handling these kind of splitting/merging operations we will do this once the repository has been gittified (Issue #86).

Original issue reported on code.google.com by `orbeckst` on 19 Nov 2011 at 4:00
* Blocked on: #86