ui: pass in formatted message to logger.log() This makes sure that all logger instances will handle the message arguments properly.

blackbox: send debug message to logger by core ui Since the core ui.log() may recurse into ui.log() through ui.debug(), it must guard against recursion. The ui extension class can finally be removed.

blackbox: change the way of deactivating the logger on write error This prepares for the upcoming code move. The recursion guard will be ported to the core ui.

match: remove obsolete catching of OverflowError Since 0f6a1bdf89fb (match: handle large regexes, 2007-08-19), we catch an OverflowError from the regex engine and split up the regex if that happens. In 59a9dc9562e2 (ignore: split up huge patterns, 2008-02-11), that was extended to raise an OverflowError in our code even if the regex engine doesn't raise it. It's unclear if there was a range of regex sizes where the OverflowError would be raised from the regex engine but that were still below the limit we added in our code. Either way, both limitations were probably removed in Python 2.7.4 when the regex code width was extended from 16bit to 32bit (or Py_UCS4) integer (thanks to Yuya for finding that out). If at least the first limitation was removed, we no longer should be using OverflowError for flow control, so this patch changes that. Differential Revision: https://phab.mercurial-scm.org/D5309