Apparently, the sender can still be null even though it's deleted
via deleteLater().

This is needed for sourve packages, but interferes with binary ones.

Task-Nr: QTCREATORBUG-1935

The code is technically incorrect and easy to fool.
See the comment in the patch.

Instead let the project explorer plugin handle that.

Reviewed-By: danimo

Task-Nr: QTCREATORBUG-2209

 * Make the name of the configuration about to be removed more visible.

 * Update the Qt name when entering the path to qmake via the text edit.
   Behaviour matches what used to happen when selecting qmake via
   the file browser now.

Task-number: QTCREATORBUG-2145

Do not save Qt versions without a qmake set. Makes no sense to keep
those.

This happened if the file is openned after the debugger has started

It's used very often, so lazy computation (potentially in the gui
thread) was too expensive.

Reviewed-by: Kai Koehne

Task-number: QTCREATORBUG-2207

This should speed up the matching between the AST nodes and the debugIds

updateUses() has to be called for cursor position changes.

Done-with: Kai Koehne

Task-number: QTCREATORBUG-2208

 * Fix the GCC output parser misinterpreting "At top level" messages
   as Errors instead of a simple message.
 * Add unit test to cover this

Task-number: QTCREATORBUG-2202

Finally.

We may want to implement a proper Ui for this. Maybe not as modal
message box.

 * Automatically reload task lists.
 * Add task handler to stop the reloading
 * Add some really simple API for other plugins to use.

Reviewed-by: hjk