Jason

fix a large number of lint warnings

update the checking pid debug message so it only gets shown once per pid, rather than being printed for every fd under the pid

rework/speed up file in use code to check all files at once so the /proc tree only has to be seached once.

fix the cleanup wizard crashing if the filename being checked contains unicode characters that can't be encoded into a string

update copywrite comment

update subprocess calls to use universal_newlines so they don't need their output converted to strings later.

fix several pylint warnings

set worstfilesystem to the first filesystem if it's not been set yet so there aren't errors due to '' not being a filesystem in the valid list