BackendModel::getExtrasForData, added $action

You can now narrow your search down with $action.
BackendModel::deleteExtrasForData, added $action
Only invalidate frontend cache when necessary
Updated changelog
Minimalized the query
Fixed typo
BackendModel:: deleteExtrasForData needed to be static
Fix for blog index page.
Changed model so that every blog entry from the getAll method (used in actions/index.php) will now also contain a boolean value 'allow_comments'.
This will be set to true when:
- the setting allow_comments for that blog entry is true
- the general blog module setting allow_comments is also true

Changed index.tpl: The comment links will only be shown when allow_comments for that blog entry is true.
Fix for recent_articles_full widget.
Only change necessary was to add a check on widgetBlogRecentArticlesFull.allow_comments. Because it uses the same getAll method from the model as the index.tpl template which was fixed in previous commit.
Fix for blog category page.
Every blog entry from the getAllForCategory method in model now also contains the boolean value 'allow_comments'.
This will be set to true when:
- the setting allow_comments for that blog entry is true
- the general blog module setting allow_comments is also true
Fix for blog entry detail page.
Here a check was already in place for displaying/hiding the section to add a comment.
I added a check on:
- listitem that displays info about the comments.
- the section that displays the existing comments for that blog entry.
Fix for archive page.
Every blog entry from the getAllForDateRange method in model now also contains the boolean value 'allow_comments'.
Added a variable to archive action called 'allowComments'. This is a boolean to indicate that the archive may display comment info at all. It reflects the value that is set in the global blog module setting for allow comments.
Modified archive template:
- added check around th. Won't be displayed when global blog setting comments_allowed is false.
- added check around td. It won't be displayed when the global blog setting comments_allowed is false or when the blog entry setting comments_allowed is false.
Pagination: added anchor

Allowing an anchor to be defined. So you can scroll to the desired
element.
Pagination: changelog updated
Spoon thumbnail: prevent black stripes when resizing.
better javascript ucfirst
Ticket 294
Blog: next and previous don't work when blog-items has same publish_on date
Bugfix: Extensions module link to default action
Ticket 316
Stop using broken custom url during installation
TagBox: Tags should be handled as strings