QmlJS tooltips: Avoid unhelpful tooltips.
QmlJS tooltips: Avoid unhelpful tooltips.

Saying 'unknown' or 'undefined' isn't very useful.

Change-Id: I130013a8f025ebc5eb984358f269fdf8a23aae92
Reviewed-by: Roberto Raggi <5b38c5be65ca2d75b92c40e91029e90f276fd4fe@nokia.com>

amyvmiwei/qt-creator,darksylinc/qt-creator,hdweiss/qt-creator-visualizer,maui-packages/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,malikcjm/qtcreator,darksylinc/qt-creator,jonnor/qt-creator,kuba1/qtcreator,azat/qtcreator,KDAB/KDAB-Creator,colede/qtcreator,richardmg/qtcreator,omniacreator/qtcreator,farseerri/git_code,xianian/qt-creator,azat/qtcreator,colede/qtcreator,Distrotech/qtcreator,amyvmiwei/qt-creator,richardmg/qtcreator,xianian/qt-creator,richardmg/qtcreator,danimo/qt-creator,darksylinc/qt-creator,malikcjm/qtcreator,ostash/qt-creator-i18n-uk,malikcjm/qtcreator,kuba1/qtcreator,KDAB/KDAB-Creator,malikcjm/qtcreator,farseerri/git_code,omniacreator/qtcreator,bakaiadam/collaborative_qt_creator,omniacreator/qtcreator,danimo/qt-creator,KDE/android-qt-creator,farseerri/git_code,malikcjm/qtcreator,bakaiadam/collaborative_qt_creator,duythanhphan/qt-creator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,xianian/qt-creator,ostash/qt-creator-i18n-uk,martyone/sailfish-qtcreator,azat/qtcreator,kuba1/qtcreator,xianian/qt-creator,ostash/qt-creator-i18n-uk,colede/qtcreator,omniacreator/qtcreator,KDE/android-qt-creator,hdweiss/qt-creator-visualizer,Distrotech/qtcreator,maui-packages/qt-creator,bakaiadam/collaborative_qt_creator,xianian/qt-creator,bakaiadam/collaborative_qt_creator,martyone/sailfish-qtcreator,colede/qtcreator,danimo/qt-creator,duythanhphan/qt-creator,danimo/qt-creator,darksylinc/qt-creator,KDE/android-qt-creator,amyvmiwei/qt-creator,syntheticpp/qt-creator,AltarBeastiful/qt-creator,colede/qtcreator,hdweiss/qt-creator-visualizer,KDAB/KDAB-Creator,kuba1/qtcreator,Distrotech/qtcreator,jonnor/qt-creator,kuba1/qtcreator,duythanhphan/qt-creator,KDE/android-qt-creator,syntheticpp/qt-creator,duythanhphan/qt-creator,farseerri/git_code,azat/qtcreator,maui-packages/qt-creator,AltarBeastiful/qt-creator,danimo/qt-creator,richardmg/qtcreator,martyone/sailfish-qtcreator,bakaiadam/collaborative_qt_creator,martyone/sailfish-qtcreator,duythanhphan/qt-creator,ostash/qt-creator-i18n-uk,colede/qtcreator,bakaiadam/collaborative_qt_creator,maui-packages/qt-creator,maui-packages/qt-creator,syntheticpp/qt-creator,omniacreator/qtcreator,omniacreator/qtcreator,amyvmiwei/qt-creator,kuba1/qtcreator,syntheticpp/qt-creator,xianian/qt-creator,KDE/android-qt-creator,AltarBeastiful/qt-creator,KDE/android-qt-creator,jonnor/qt-creator,azat/qtcreator,duythanhphan/qt-creator,Distrotech/qtcreator,bakaiadam/collaborative_qt_creator,ostash/qt-creator-i18n-uk,richardmg/qtcreator,darksylinc/qt-creator,darksylinc/qt-creator,malikcjm/qtcreator,maui-packages/qt-creator,darksylinc/qt-creator,malikcjm/qtcreator,Distrotech/qtcreator,duythanhphan/qt-creator,richardmg/qtcreator,ostash/qt-creator-i18n-uk,KDAB/KDAB-Creator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,KDAB/KDAB-Creator,xianian/qt-creator,danimo/qt-creator,kuba1/qtcreator,ostash/qt-creator-i18n-uk,kuba1/qtcreator,farseerri/git_code,azat/qtcreator,Distrotech/qtcreator,jonnor/qt-creator,amyvmiwei/qt-creator,farseerri/git_code,hdweiss/qt-creator-visualizer,syntheticpp/qt-creator,omniacreator/qtcreator,richardmg/qtcreator,darksylinc/qt-creator,AltarBeastiful/qt-creator,colede/qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,farseerri/git_code,farseerri/git_code,hdweiss/qt-creator-visualizer,jonnor/qt-creator,amyvmiwei/qt-creator,kuba1/qtcreator,xianian/qt-creator,hdweiss/qt-creator-visualizer,syntheticpp/qt-creator,jonnor/qt-creator,KDE/android-qt-creator,danimo/qt-creator,KDE/android-qt-creator,AltarBeastiful/qt-creator,maui-packages/qt-creator,xianian/qt-creator,syntheticpp/qt-creator,KDAB/KDAB-Creator,Distrotech/qtcreator