Investigate and fix usage of ! in paths

[tsuoanttila]

The UI and View Providers in CDI have some kind of support for using ! as a view separator. The logic in these internal parts need to be gone through with thought and fix any potential pit falls and issues.

[Darsstar]

Some options I can think of:

• Refactor current functionality somehow.
• Ban View paths from starting with a !. Which would, I believe, make things cleaner.
• Stop treating ! as a special character, which both 1.x and 2.x do. I am pretty sure that before 1.0.0 parsing the UI mapping happend based on the whole URI, including protocol and fragment parts. But still before 1.0.0 it was changed to parsing path info string, so no fragment, but left the !-means-there-is-a-hashbang-so-lets-ignore-that-part logic.
  • I felt that leaving the ! logic in place without it doing anything useful is stupid. Which is why I created a pull request to make it do something I thought could be useful.
    • I probably did a poor job at communicating that just dropping the ! logic would also be fine as far as I am concerned.