all: unmark experimental features

It's been some time now we've had those features, so unmark them
being experimental.

It does not mean everything is perfect, but may gather some more
testing of those features.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 reporter_name="Yann Diorcet <diorcet.yann@gmail.com>"

 reporter_url=""

 reporter_comment="Config to build cross-compiler with mingw as kernel type for

 64 bits Windows target"