suggestions of improvement

[phyto]

Thank you very much for pygenomeviz!! I like it a lot!!
I have two suggestions though:

1. I am working with genomes that are sometimes fragmented. I frequently want to align vertically the contigs that are displayed, by taking a specific position as reference for vertical alignment. The attribute ".align_type" ('left', 'center', 'right') of Genomeviz is of no help, as contigs are not aligned as I would like. Currently I am using a script that provides a turnaround for this, by calculating a ._track_offset value for track objects, and intercepting _get_track_offset() of Genowiz objects to use ._track_offset value instead of value calculated py pygenowiz. But to make things simpler, I would suggest that user should have the possibility to define their own track_offset for each track, in order to realize a vertical alignement as desired.
2. I like the functionality to define facecolor for each gene by using facecolor_handle_func when executing track.add_genbank_features(). However, I would like to go further and also adjust edgecolor and patch_kws at the same time. Therefore I would suggest to include something like a "patch_kws_handle_func" that would return a dict that is feature-dependent. Another, more flexible possibility would be to provide a "appearance_handle_func" that would contain facecolor, edgecolor, patch_kws, etc depending on the feature being added. Of course it is possible to monkey-patch pygenowiz to do this but I thought it would be better to let you know the idea.
   Anyway thank you for this nice and useful tool!!

[phyto]

typo for "appearance_handle_func": please read "appearance_handle_func" would return a dict containing facecolor, edgecolor, patch_kws, etc.