2 more examples working..

Fixed with update to nml2 comp type defs & examples here:
https://github.com/NeuroML/NeuroML2/commit/31322778bceb5f45d48ae7f26c883227dc3d8756
Issues down to change of g from DerviedVariable to StsteVariable in
expOneSynapse & mismatch in passiveChan name in Ex6&7
Syncing examples with those in jLEMS & LEMS repositories
Defaulting to whichever is the local install of python
Fixed bug in use of scale in Unit; added test with hour & min units
Merge pull request #9 from LEMS/development

Latest development branch; most stable version