Fix bug in https://bugzilla.redhat.com/show_bug.cgi?id=1018635
fix up wordings, refactor maps, lists to use generic type
Remove checking of null in compareTo method
Change type to generic
Fix up compareTo method
Fix project stats not updated
fix unit test
Merge pull request #226 from zanata/document-list-statistic

Fix bug with unexpected behaviour of hours remaining value on filtering

https://bugzilla.redhat.com/show_bug.cgi?id=1018635