Add Qt Canvas 3D tech preview repository configurations

Change-Id: Ic7c3226484ad93db86974b406d9169b0b9d48895
Reviewed-by: Iikka Eklund <iikka.eklund@theqtcompany.com>
Adding MinGW 4.9.1 for Android builds.

Change-Id: I2d602136ecbe19a77359a5e27f90337161c559ba
Reviewed-by: Antti Kokko <antti.kokko@digia.com>