Also introduce a indirection, modes have now types, edit and debug have
the same type, and editors do have a prefered type of modes instead of a
prefered mode.

That fixes the bug that if the prefered qml editing mode was set to
design, then in switching between qml editors would
- in Edit Mode: stay in edit mode
- in Debug Mode: switch to debug mode

Task-number: QTCREATORBUG-2300

Required refactoring of the search result window to show real trees of
search results.

The backend is the backend from the Locator filter, which is a bit
outdated now.

Reviewed-by: Roberto Raggi

OK, it seems that this change is not necessary.

This reverts commit 40bae63c.

Done-with: Erik Verbruggen

Done-with: Roberto Raggi

Fixed crash in FindUsages on a dirty file in a large project, which is saved
while the FindUsages is still running.

Reviewed-by: Erik Verbruggen

This uses the same UI as "Rename Symbol".
Moves the actual rename implementation to a static method in
BaseFileFind and uses it for rename symbol and search & replace.
Moves the signal notification for the code model from VCSManager to
the more general FileManager.
Note that as for rename symbol, there's no undo yet.

Task-number: QTCREATORBUG-73

Encapsulate the details.

Move the API to the progress manager.
Added a first Mac implementation, other
platforms are pending.

Ensure the code model receives file names with clean paths ('/')
and fix paths in the relevant places of the code model. Pass on clean
paths from Cpp reference find and display them correctly in the search
window tooltip.

Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>