render side with most synapses

[floesche]

For neuron types whose contra lateral innervation is larger than the ipsi lateral, it now looks like this:

instead of

Other neurons will also highlight the side for both, the celltype and ROI, in color.

The ROIs will be show in the correct location in the combined page. This also means, the Left cell will show on the "right side", the right cell on the "left side":

Also, the eyemaps for left and right side now have the same size.

This partially addresses #52

[leburnett]

Works well for CT1 and DNc02 and is a good solution. I tried aMe12 because I knew that that was a bilateral cell but, as you mention, this fix is only for cells that predominantly innervate the contralateral side. Capturing the innervation of bilateral cells in both hemispheres is out of the scope of this PR. Merging in now.