Hg issue 214: tests failure when using python debug flavor
Further tweaks re error handling.
2016.6.14
Not secure
Hg issue 213: Segmentation Fault
Info about atomic groups wasn't pushed properly.
2016.6.5
Not secure
Hg issue 212: Unexpected matching difference with .*? between re and regex
In 'add_repeat_guards', it wasn't propagating the status from the tail back towards the head across default nodes, so the guards weren't always correct.
2016.6.2
Not secure
Hg issue 211: Segmentation fault with recursive matches and atomic groups
It wasn't saving the call frame and then restoring it when backtracking out of atomic groups.
2016.5.23
Not secure
Hg issue 206: Incompatible with re if single { in the pattern
Brought the regex module's handling more in line with the re module. It now more readily treats an invalid fuzzy constraint as a literal.