This was a regression introduced in 8e4fb678
triggersCompletion should return `true' when the token at the left of the T_LPAREN
is an identifier, a SIGNAL, a SLOT or T_GREATER (for template functions).

columnNumber() relies on text wrapping, and we're only interested in the
position of the cursor in the block.

Also removed TokenUnderCursor as it's functionality is in the token cache.

Reviewed-by: ckamm

This reverts commit c2393df0.

This should speed things up a bit, because before, the line was tokenized at
least 3 times.

Don't sort the global completion items when we have too many of them, instead
populate the completion box in a way where local symbols are showed before
global symbols.

This reverts commit 13a721d9.

This reverts commit bb35b4d0.

To only run if the pound/hash sign is at the start of the line.

This reverts commit e4fb53e8.

Should have gone into master, not into the 2.0 release branch.

By moving the completion settings into the TextEditor plugin, so that
both the CppTools and the QmlJSEditor plugins can access the settings.

The user-interface to edit the settings is still in the CppTools plugin,
since we're in string freeze at the moment. It should be moved to the
TextEditor plugin later.

For now the QML completion only supports the case-sensitivity and
partial completion options, since there is no automatic insertion of
brackets.

Task-number: QTCREATORBUG-1327
Reviewed-by: Daniel Molkentin <daniel.molkentin@nokia.com>