Initialisation of agent using variable expression doesn't work

[davidcsterratt]

I've discovered that SpatialKappa doesn't work quite the same way as KaSim when it comes to initialiasing agents. Hopefully the following code snippet demonstrates the issue.

%var: 'vol' 0.1
%var: 'NA' 6.02E23
%var: 'CaMinit' (100*'NA'*1E-21*'vol') # Doesn't work in SpatialKappa but does in   KaSim
#%var: 'CaMinit' 6022.1 # Works in both
#%var: 'CaMinit' 6022   # Works in both 
%init: 'CaMinit' CaM(n1,n2,c1,c2)

This is not a critical problem, but it would be nice to fix.