verify: initialize rp variable in case we hit out of memory

merge: drop reference to file contents after write This reduces memory usage on large consecutive gets.

revlog: drop cache after use to save memory footprint If we reconstruct back to back large versions, we need to drop the cache first to avoid doubling memory usage.

verify: reduce memory footprint when unpacking files By never holding a reference to the unpacked string, we avoid holding two consecutive large files in memory.

verify: report exceptions that don't have a str() method

color: fix test-diff-color breakage

hgcia/color: remove star imports This plays nicer with demandimport and allows pyflakes to detect undefined names.

hgfixes: added a fixer that makes bytes to be formatted correctly This patch implement a fixer that replaces all calls to the '%' when bytes arguments are used to a call to bytesformatter(), a function that knows how to format byte strings. As one can't be sure if a formatting call is done when only variables are used in a '%' call, these calls are also translated. The bytesformatter, in runtime, makes sure to return the "raw" % operation if that's what was intended.