Added a version of CSAConnector for the NEST backend that just passes down the CSA object to PyNEST's CGConnect() function. Weight and delay handling is still missing.
Merge remote branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/jougs/PyNN
implemented connectors for pyNN.nest backend, adapted projection class accordingly and added NativeRNG class for pyNN.nest backend
Merge https://github.com/NeuralEnsemble/PyNN into commit_nest_connectors

Conflicts:
	src/nest/projections.py
fixed imports in src/nest/connectors.py
fixed layout issues in src/nest/standardmodels/synapses.py
fixed NewConnect -> Connect to adapt to name changes in NEST
removed NEST_SYNAPSE TYPES construction
fixed layout in nest/standardmodels/synapses.py
Update recording.py

Adapted NewConnect -> Connect
Update projections.py

Fixed comment in projection._connect().
inserted type conversion when creating poisson generators with parrot neurons because the new nest Connect function is sensitive to this
Merge branch 'commit_nest_connectors' of github.com:mschmidt87/PyNN into commit_nest_connectors
Merge remote-tracking branch 'upstream/master'
Added warning if NEST was not compiled with libneurosim.
NEST 2.4 renamed parameter 'type' -> 'node_type'

* For backwards compatibility both 'type' and 'node_type' are ignored
  for now
Merge pull request #316 from obreitwi/master

NEST 2.4 compatibility
Merge pull request #313 from jougs/master

Add optimized CSAConnector iterating connection-sets in NEST