Impliment RegEx debugging facility

[Nehemiah I. Dacres]

http://stackoverflow.com/questions/101268/hidden-features-of-python#143636

re.compile("^font(?:=(?P[-+][0-9]{1,2}))?[/font]",
re.DEBUG)
at at_beginning
literal 91
literal 102
literal 111
literal 110
literal 116
max_repeat 0 1
subpattern None
literal 61
subpattern 1
in
literal 45
literal 43
max_repeat 1 2
in
range (48, 57)
literal 93
subpattern 2
min_repeat 0 65535
any None
in
literal 47
literal 102
literal 111
literal 110
literal 116