Update pyload.py

fixed http://flexget.com/ticket/2527
A more reliable exists plugin

The plugin currently compares entries and files/folders by title, but
the entry title for a file usually doesn't include its extension, so is
pratically impossible rely on exists when task input is provided by
find, listdir and several other plugins.
Added plugins to copy and delete files

"move" has been updated too.
Just a missing pathscrub
Changes in error handling
Missing spaces
Updated dnspython module name
FIX urlrewrite_torrentleech bug NONType contents

Add size Terabyte to size parser
fix a bug with 'file_exts' option

torrent file won't be downloaded in default,because of a 'not'.
Edited the transmission plugin so that it can handle transmission internal limits for seed ratio and idle time, they are applied by default on the input plugin when onlycomplete is true, and optional in transmission_clean with transmission_seeds_limits
renamed transmission_seeds_limits config key to transmission_seed_limits, corrected pathc to comply pep8
forgot to rename entry in option validator in transmission plugin
Merge pull request #283 from BrainDamage/transmission_seed

Improvements to transmission plugin
Get back function validate_config() webui need
update urlrewrite_newpct.py url

Updated return link to reflect the new www.newpct1.com links. (old url was working but wrongly matching the tv shows)
Merge pull request #285 from kabracity/patch-2

update urlrewrite_newpct.py url
Merge pull request #280 from wicastchen/patch-2

fix a bug with 'file_exts' option in aria2 plugin
Merge pull request #279 from Shorny/master

FIX urlrewrite_torrentleech bug (NONE Type contents)
Merge pull request #250 from explo910/patch-1

pyload plugin updates, fixes #2527
Merge pull request #258 from tarzasai/fix_exists

A more reliable exists plugin