Bug fixes, recording and save

- Bugs in equations
- Bugs in units
- Saves spike trains and v traces
Added override notation
Bug fixes and parameter changes

Reduced duration for testing
Fixed delay calculation
Receptors now spike

Neglected to make receptors spike and was propagating potential instead.
Added monitor for x variable, for debugging and testing
Delayed spike propagation
Save method handles conversion: ArrayList -> String
Fixed many more bugs

- Was missing refractory period
- Appears to run properly (further testing required)