Editor: Do not highlight invalid Uses
Editor: Do not highlight invalid Uses

Invalid Uses (line == 0) are generated by e.g. a Q_D statement.

This kills
 1. the selection artifact in line 0, column 0 and
 2. the warning "QTextCursor::setPosition: Position '-1' out of range"

for the following example code and cursor position:

    void f()
    {
        Q_D(x)
        d->hello(); // put the cursor on the 'd'!
    }

Change-Id: I6968cbc261f05e08f71ff125437c8c9e863b475b
Reviewed-by: Erik Verbruggen <5edfe905d082749f2ac3f4e6b42937f39f083771@digia.com>

duythanhphan/qt-creator,farseerri/git_code,kuba1/qtcreator,xianian/qt-creator,malikcjm/qtcreator,xianian/qt-creator,danimo/qt-creator,darksylinc/qt-creator,darksylinc/qt-creator,danimo/qt-creator,maui-packages/qt-creator,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,duythanhphan/qt-creator,omniacreator/qtcreator,malikcjm/qtcreator,omniacreator/qtcreator,farseerri/git_code,amyvmiwei/qt-creator,malikcjm/qtcreator,xianian/qt-creator,danimo/qt-creator,Distrotech/qtcreator,kuba1/qtcreator,danimo/qt-creator,Distrotech/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,malikcjm/qtcreator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,malikcjm/qtcreator,martyone/sailfish-qtcreator,colede/qtcreator,duythanhphan/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,duythanhphan/qt-creator,maui-packages/qt-creator,colede/qtcreator,colede/qtcreator,richardmg/qtcreator,colede/qtcreator,richardmg/qtcreator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,colede/qtcreator,kuba1/qtcreator,xianian/qt-creator,colede/qtcreator,xianian/qt-creator,maui-packages/qt-creator,Distrotech/qtcreator,malikcjm/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,maui-packages/qt-creator,martyone/sailfish-qtcreator,kuba1/qtcreator,kuba1/qtcreator,Distrotech/qtcreator,amyvmiwei/qt-creator,xianian/qt-creator,richardmg/qtcreator,farseerri/git_code,kuba1/qtcreator,darksylinc/qt-creator,farseerri/git_code,colede/qtcreator,xianian/qt-creator,omniacreator/qtcreator,danimo/qt-creator,Distrotech/qtcreator,maui-packages/qt-creator,maui-packages/qt-creator,omniacreator/qtcreator,amyvmiwei/qt-creator,xianian/qt-creator,farseerri/git_code,martyone/sailfish-qtcreator,duythanhphan/qt-creator,omniacreator/qtcreator,darksylinc/qt-creator,richardmg/qtcreator,AltarBeastiful/qt-creator,danimo/qt-creator,darksylinc/qt-creator,richardmg/qtcreator,darksylinc/qt-creator,kuba1/qtcreator,maui-packages/qt-creator,martyone/sailfish-qtcreator,duythanhphan/qt-creator,kuba1/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,danimo/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,malikcjm/qtcreator,farseerri/git_code,darksylinc/qt-creator,richardmg/qtcreator,omniacreator/qtcreator,Distrotech/qtcreator,Distrotech/qtcreator,amyvmiwei/qt-creator,kuba1/qtcreator,darksylinc/qt-creator,richardmg/qtcreator,duythanhphan/qt-creator,omniacreator/qtcreator