extend module classes for helping with some default module categories

I'd like to start getting all of us the habit of using categories (does not matter much which!) so that we can cope with the many automated builds (esp. in light of upcoming toolchains).

If someone doesn't like this style it can be easily over-riden with --amend=moduleclass=foo

Signed-off-by: Fotis Georgatos <fotis.georgatos@uni.lu>