Cache clean will remove the publishing directory directly and not on the queue.
A check done before the queue is run resulted in false positives for spritesheet modification dates.

Some mild code formatting for blocks.
Fix for non publishing of obviously dirty smart sprite sheets.
Changing the values of a smart sprite sheet to the default value(like 0 or false) resulted in no dirty mark. That led to skipped publishing of that particular resource.
Issue: Default values are not stored explicitly in the project settings rather as absent value. That led to a code branch where mark as dirty was not invoked.
Removing a value for a resource is change and therefore marks it as diry.
Test added for publishing twice without cleaning inbetween or changing anything.
Related github issue #779.
Removed some debug comments.
Refactoring: Used literals for BOOLs.
Test for changed markAsDirty behaviour for removeObjects added.
Refactoring: Using literal syntax.
Merge pull request #786 from NickyWeber/bugfix/#779_smartsheet_not_published_at_first

Bugfix/#779 smartsheet not published at first