Cannot remove/derive because they differ slightly:
objects.cpp
statemonitor.cpp

Cannot remove/derive (differ substantially):
spikegenerator.cpp
spikemonitor.cpp
ratemonitor

Removed (now derived):
common_group.cpp
common_synapses.cpp
group_variable_set.cpp
group_variable_set_conditional.cpp
synapses_classes.cpp
synapses_create.cpp
synapses_create_array.cpp

Removed (not used in brian2genn):
main.cpp 
run.cpp
stateupdate.cpp
makefile
network.cpp
reset.cpp
run.cpp
spatialneuron_prepare.cpp
spatialstateupdate.cpp
stateupdate.cpp
summed_variable.cpp
synapses.cpp
synapses_initialise_queue.cpp
synapses_push_spikes.cpp
threshold.cpp
win_makefile

GeNN-specific templates:
GNUmakefile
WINmakefile
engine.cc
model.cc
runner.cc
synapses.cc
# The following templates are *not* used for NeuronGroup
reset.cc
stateupdate.cc
threshold.cc
# This template merges the code for stateupdate/threshold/reset in
# NeuronGroups (in GeNN, they all share the same support Code)
neuron_model.cc


