Unbreak moving WavPack correction files

The `settings` argument to `File._rename` has been removed in 7c4fdf76.
File._rename: Return early if the new filename is the same as the old one

This is mostly for readability.
Fix up format error introduced c6494fa18f941e578a2985af1c916b411a5a13c3
Merge pull request #144 from zas/config_upgrade_fix1

Fix up format error
logview: remove log receiver when dialog is closed
logview: limit number of lines stored in memory to 50000
log, logview: use levels instead of prefixes and colorize log view output
log: use bitwise operators for log levels matching
_entries -> entries as it is used outside log module
logview: enable minimize/maximize for log dialog windows
logview: code cleanup
Let the receiver convert time to string.
_stderr_receiver(): include ':' in format string instead of each dict entry
Drop currentThreadId in stderr output
Merge pull request #143 from zas/logview

Improve logging code and display
Use QThreadPool for threading
Don't throw an AttributeError if no discid module is available

The cd lookup button was enabled even if no discid module was available,
don't do that.

Additionally, display information about the missing discid module in the
About window.

This fixes PICARD-510
Regenerate picard.pot
_save_images: `continue` after deciding a file doesn't need to be saved

The previous code was `return`ing from the function, so images after the
first already existing one were not even considered for saving.
Add '/' to _escape_lucune_query in webservice.py

Due to Lucene 4 updates, this is necessary.