fix double slash prepending causing troubles on WinCE
fix double slash prepending causing troubles on WinCE

Before adding a / to the path one should check if it doesn't end with
one already. Otherwise one might get paths like //My Documents on
WinCE causing the native call to crash the filesystem service on that
system.

Reviewed-by: alexis

KDE/qt,radekp/qt,KDE/qt,KDE/qt,igor-sfdc/qt-wk,RLovelett/qt,radekp/qt,RLovelett/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,KDE/qt,KDE/qt,KDE/qt,radekp/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,radekp/qt,RLovelett/qt,RLovelett/qt,RLovelett/qt,igor-sfdc/qt-wk,radekp/qt,radekp/qt,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,RLovelett/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,radekp/qt,pruiz/wkhtmltopdf-qt,KDE/qt,RLovelett/qt,RLovelett/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt