Add 'type' on plugin.json files
Update change:set-document-root parameters

Now set webBaseDirectory and webBaseURLPath configuration keys
Update DbProvider injection process
Add \Change\Workspace::composeAbsolutePath()

Refactor usage of relative path in configuration
Fix relative path management.
Fix relative path management.
Fix relative path management.
Merge pull request #518 from inthause/documents

Some refactoring