[gentoo-dev] huse: new helper for low level eclass writers

[Mike Frysinger]

i wrote a new func for toolchain.eclass: huse.  this is because the 
toolchain.eclass supports multiple versions in parallel, and the IUSE value 
can vary greatly between them.  so doing `use foo` without checking IUSE first 
doesn't work.  since i got a request to use this in other eclasses (for the 
same reason), i figured i'd move it to eutils.eclass so more people can benefit.

now that we have "in_iuse" in eutils.eclass (with all the caveats), i'll be 
adding huse:
	huse() {
		in_iuse $1 || return 1
		use $1
	}

any comments before i publish ?
-mike