Merge remote-tracking branch 'origin/no_more_spikes' into codegen_improvement
Added some notes on passing variables to templates
Make refractoriness tests also run with C++ code generation, change return type of the int_ function to int
Merge pull request #101 from brian-team/codegen_improvement

Various codegen improvements
Merge branch 'master' of https://github.com/brian-team/brian2.git into devices2