GL Extension test: Do not check for GL_OES_mapbuffer

This extension is not required anymore.

[tests] Do not check for GL_OES_mapbuffer

Signed-off-by: Thomas Perl <thomas.perl@jollamobile.com>
EGL Extension test: Check for extensions required by Wayland

[tests] Check for WL_bind_wayland_display and KHR_image_pixmap

Signed-off-by: Thomas Perl <thomas.perl@jollamobile.com>
GLSL: Add explicit cast to float

I'm not entirely sure why the format string "%.2f" would not print the
fractional part of the number, but this is what happens, so to avoid
type mismatches, we add an explicit cast to float.

[tests] Fix convolution filter test by adding explicit cast

Signed-off-by: Thomas Perl <thomas.perl@jollamobile.com>