Allow references to pre/post variables in expressions used to set synaptic state variables.
Allow references to pre/post variables in expressions used to index synaptic state variables.
Allow references to pre/post variables in synaptic model equations
Fix use of pre/post variables with subgroups
Allow references to pre/post variables when creating synapses
Fix the template for a combination of connection mask and probability
Add an example showing the use of string expressions for spatial connectivity
Re-add the unit checking for string assignments that was accidentally removed at some point
Merge branch 'master' into fix_pre_post_references
Merge pull request #108 from brian-team/fix_pre_post_references

Allow pre/post references in synaptic expressions