Use 'hg log --date' for changelog generation on a date range

The current implementation of the ChangeLogCommand for hg repositories first gets the commit info for the complete repository, only filtering on the dates afterwards in the Java level. The 'hg' binary has the option --date since version 0.9.2, which is the version listed as the minimum version this provider is compatible with.

Running "hg help dates" gives you an overview of the options one has to specify a date range on the command line. The provider should be updated to use the 'hg' feature instead of filtering itself.