freetype: fallback to the system font if no font is specified in the style (fix #8960)

This fixes a potential NULL pointer dereference and also enables the marq
filter to use the user specified font.

Reported-by: Tillmann Karras <tillmann@selfnet.de>

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
Qt5: Be sure to use the rcc/moc/tools of Qt5

Ref #8532
Qt5: Fix ADD_ICON, again
Qt: toAscii has been deprecated

Ref #8532
Qt: do not delete speedControl yourself

It is a QFrame, so it is already parented and should work fine.
Fixes crash-on-quit in Qt5