Added check for error in fold_case which, I hope, will reveal the exception that it's not reporting.
2016.9.22
Not secure
Hg issue 220: Misbehavior of group capture with OR operand
Repeats should not be factored out of branches because a branch should be exhausted before trying the next one.
2016.9.13
Also supported on Python 3.6.
2016.8.27
Not secure
Hg issue 219: Unicode word boundries
For a Unicode word boundary (UAX 29), apostrophe in rule WB5a should include both U+0027 (APOSTROPHE) and U+2019 (RIGHT SINGLE QUOTATION MARK / * curly apostrophe).
2016.7.21
Not secure
Hg issue 217: Core dump in conditional ahead match and matching \! character
Fixed bug where it incorrectly tried to restore saved groups when none saved.
2016.7.14
Not secure
Hg Issue 216: Invalid match when using negative lookbehind and pipe
The creation and position of a branch firstset wasn't always correct.