match: add optional warn argument Occasionally the matcher will want to print warning messages instead of throwing exceptions (like if it encounters a bad syntax parameter when parsing files). Let's add an optional warn argument that can provide this. The next patch will actually use this argument.

match: add source to kindpats list Future patches will be adding the ability to recursively include pattern files in a match rule expression. Part of that behavior will require tracking which file each pattern came from so we can report errors correctly. Let's add a 'source' arg to the kindpats list to track this. Initially it will only be populated by listfile rules.

check-code: reintroduce str.format() ban for 3.x porting In their infinite wisdom, the Python maintainers stripped bytes of its % and format() methods for 3.x. They've now added % back to 3.5, but format() is still missing. Since we don't have any particular need for it, we should keep avoiding it.

util: drop the 'unpacker' helper It is not helping anything anymore.

MBTextWrapper: drop dedicated __init__ method It was only there as a compatibility layer with a version of Python which we do support anymore.

util: drop the compatibility with Python 2.4 unpacker Python 2.4 compatibility have packed and sailed.

tests: just use 'response.reason' There is no reason to not have simple code now that Python 2.4 is dead.

url: drop awful hack around bug in Python 2.4 It's all just a memory now.

httpconnection: drop Python 2.4 specify hack Python 2.4.1 doesn't provide the full URI, good for it.

mail: drop explicit mail import required by Python 2.4 He's dead, Jim.