Added the possibility to specify own copy-of names for files as an alternative to the ones defined in translation files (CH-182). Changed default copy-of names in english and polish translations so that always start with %name instead of word "Copy".
Fixed several cosmetic code issues. Improved detection of same/different disk detection. Switched shared_ptrs to use std implementation instead of boost one. Cleaned up includes in headers. (CH-259)
Bugfix: pausing/resuming task did not take already processed part of files into account. That caused resuming to ask for file replacement when unnecessary (CH-140).
Rewritten statistics handling for sub tasks, tasks and task manager (this commit introduces some issues that needs to be further fixed). Only basic tests performed (!)