Take it as an expected file change.

External 'sort' now works as it should.

* Handle <input> tag.
* Pass input to running process.
* Search for executable in path.
* Add "CurrentSelection" variable.

Remaining issue: ReplaceSelection output handling.

Most of the output handling, error handling etc is missing atm.

For now that removes the CURRENT_DOCUMENT variable and derivates.

Reviewed-by: Kai Koehne

This is in line with the other buildstep UIs.

Reviewed-by: dt

QtDeclarative checks for the capitalization of .qml files. This might fail
for relative pathes if the working directory is not capitalized like on disk
(QTBUG-17529).

Task-number: QTCREATORBUG-3722
Reviewed-by: dt

Removing an object watch might fail if e.g. the app crashes in between.

Leave event would close the widget.

Remove duplicate code, proper messages, linguist comments.

Task-number: QTCREATORBUG-3821

Otherwise it's possible to remove the tool bar without ever getting it
back.

Only the ClientProxy uses it anyway.

Reviewed-by: Thorbjorn Lindeijer

Seems it's not only theoretically possible but people actually want to use it

Task-number: QTCREATORBUG-3813