Priority inclusions and checks for a v0.1 release

[dww100]

1. Fixtures/file associations: Need a way to deal with common (to multiple runs i.e. Shared files for Campaigns #11) and large files.
2. A very simple VVP - to allow testing only
3. Some tests
4. Categorical variables
5. Decide on where aggregation code should be (currently an analysis UQP)
6. Fix issues:
   • Allow generic encoder to use a symbol other than $ #24
   • Add a uniform distribution that produces integers #25

[dww100]

Note: This assumes acceptance of #19 [Now accepted]

[dww100]

On point 5. we should just create an aggregation or collation module on a par with uqps and vvps.