refactored & fixed plugin signals
Fix unique constraint violation and UnicodeEncodeError in publisher_publish command
Fix publisher_publish tests on Django 1.4
Add test for is_current_app toolbar flag
Fix corruption of cached template nodelist by placeholder scan.

get_placeholders() modifies the nodelist of a parsed template without
taking a copy. With non-caching template loaders this doesn't matter, but
with Django's caching template loader, the same template, with modified
nodelist, will be used next time the template is requested.

The main issue with this is that blocks inherited from a parent template,
and not overridden, appear as though they were copied literally into the
child template. Often this doesn't matter, but if the block uses block.super
and adds content, then because it's interpreted twice, the added content
will appear twice.
Fix determining current app
Merge pull request #3411 from yakky/feature/fix_current_app

Fix current app detection
Merge pull request #3407 from Pankrat/develop

Fix unique constraint violation and unicode error in publisher_publish command
Merge pull request #3409 from aptivate/fix_template_cache_corruption

Fix corruption of cached template nodelist by placeholder scan.
Merge pull request #3405 from o-zander/fix/plugin-signals

refactored & fixed plugin signals
Added failing test