[CSTP] Possible STP time delay bug

[nmsutton]

In snn_gpu_module.cu, the code comment "FIXME should be adjusted for delay" for the line setting "ind_minus" value indicates that synaptic delays greater than 1ms have not been implemented in STP calculations. It appears this may affect all STP processing (connection-specific and non-specific). While synaptic delays may be processed in other code calculations, at least in STP calculations they may be missing. 1ms delays may work correctly with the code. This possible issue should be investigated and perhaps a note can be made about this not yet working in the user guide/docs for STP/connect() function in CARLsim.

In the main branch CARLsim code's snn_manager.cpp (verifyNetwork()) there is a check for STP being enabled and delays > 1 with the error "STP with delays > 1 ms is currently not supported." In the feat/ca3net CARLsim branch, when JK_CA3_SNN is enabled (code for CA3 net) this error is disabled. Therefore the ability to have STP with delays greater than 1 ms may only be possible in the feat/ca3net branch code. In that branch's code possibly delays >1 with STP are not processed correctly.