content types can read own parameters

With this changes, content types can now read their specific (form)
parameters easier.
That way, third parties may get along without event listeners on
`\cms\acp\form\ContentAddForm` for more complex content types.
Merge pull request #72 from ray176/contentTypeImprovements

content types can read own parameters
fix number of ?
Merge branch 'master' of https://github.com/codeQuake/Fireball.git