Add basic import action

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Update blog model to have the insertCompletePost method

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Extend the import action with links, categories, users, images

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Make sure a posts SEO settings are filled in

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Correct option for comments that are still in moderation status

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Get the filter value from the form

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Remove unused functionality

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Use symfony filesystem component instead of spoon

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Add filter for comments text

Signed-off-by: Toon Daelman <toon@sumocoders.be>
Fix token after using datagrid sorting functions
Add correct entries to the installer
Add locale for the new action
Syntax error fix

Parse error: syntax error, unexpected 'else' (T_ELSE) in backend/modules/blog/ajax/add_category.php on line 50.
Somehow a merge gone wrong couple of months ago.

Fixed by commiting the correct version.
Small dutch translation fix

Updated dutch message:
De gebruiker mag een afbeelding.
into:
De gebruiker mag een afbeelding toevoegen.
Merge pull request #621 from bart-lysander/patch-3

Small dutch translation fix
Merge pull request #619 from bart-lysander/patch-2

Syntax error fix
Merge pull request #613 from WouterSioen/fix-token

Fix token after using datagrid sorting functions
Merge pull request #610 from turanct/import-wordpress

Import from wordpress
Fixed syntax. Was invalid after merge