Code reorganization - mainly management of file moving/copying/renaming

I began to work on the clean-up, so far I managed to maintain (more or less) the same functionality, almost all tests pass - except for test_forcefully_moving_default and test_forcefully_moving_disabled, which sometimes pass and sometimes fail, I think the order of input files isn't preserved - maybe some change to test helpers required?
(Oh, the tests fail because now first the filename is constructed and then moved, originally the file was first renamed and then moved.)

One other test that always fails on my platform is test_unicode_in_inputname - tvnamer generates filename as 'The Big Bang Theory - [02x07] - The Panty Pi\xf1ata Polarization.avi'.

There's still a lot of work to be done, merge when ready... Until then, any comments appreciated.