Managing git/svn/cvs... ebuilds

[catkfr]

I have a few ebuilds downloading git/svn/cvs/hg... sources. One example is media-tv/v4l-dvb-hg but I also use some other coming from overlays. These never get updated and I need to remember to remerge them if I want to use the latest live sources.

So, I am wondering:
1. Is there a way to list all the live ebuilds installed on a system?
2. What is the best way to update these ebuilds?

I guess there is no right answer to the second one so what would you do? I'm thinking of writing manual scripts per application pack (one for v4l-dvb-hg, another for compiz-fusion and all its dependencies...)

[desultory]

Moved from Portage & Programming to Duplicate Threads, this has already been discussed in topic "9999".