Add tests for IssueIdentifier
Change tags to a set from a string
Add copy and replace convenience functions on GenericMetadata
Update deprecated resampling code for Pillow
Change comicvine test data to be the same as the test comic
Cleanup tests
Cover image scaling now uses the smooth transformation option in Qt
Filename parsing now identifies a single number as a filename
e.g. '52.cbz' gets parsed as issue: 52 and series: 52