Fix for missing gaps when generating an alignment table from collation
of a pretokenized witness set.
Made parallel segmentation switchable.
* Fixed compatibility issue when rendering HTML or SVG with IPython 2.1
instead of IPython 0.13.
* Corrected RST syntax in package info description.
* Added extra unit tests.
Added JSON output to collate method.
Added table output to collate_pretokenized_json method, next to the
already existing JSON output.
Cached the suffix and LCP arrays to prevent unnecessary recalculation.
Updated alignment unit tests to the new API.
Prepare new developer release.