[gentoo-dev] do not rely on internal variables used by portage functions

[Mike Frysinger]

we've noticed that many things in the tree abuse the fact that the portage 
helpers utilize environment variables to communicate ... for example, people 
setting DOCDESTTREE by hand rather than using `docinto`

unless some one can give me a valid reason for this stuff, the plan is to fix 
these ebuilds and change portage internals so those vars dont exist
-mike