[gentoo-dev] emerge, ebuild completion update....

[Zach Forrest]

I've made a few enhancements to the completion code. Here is the list:
- fixed the default bash completion problem (the "-o default" option
   needs to be specified in the original compspec)
- added "digest" option to ebuild
- added other emerge options (including "--clean" and "rsync")
- you can now specify more than one option to emerge
- "--usepkg" can now be used anywhere in command line and must be
   followed by a package name or path using default bash completion
   (is this the correct behaviour?)

I also added my own "epurge" function to unmerge multiple packes. It 
behaves in a manner quite similar to emerge and also saves typing 
"ebuild /var/db/pkg/pkg-ver/pkg-ver.ebuild unmerge" for every package. 
It first completes on categories in /var/db/pkg and then on a package, 
which includes the version number. epurge will then make sure that the 
necessary ebuild files can be found and report any errors *before* 
unmerging any packages. You can also pass the "--pretend" option, which 
I _highly_ recommend using before actually unmerging any packages. This 
function only works if you source the gentoo.completion file, which also 
provides the completion code for epurge. Please use this with care -- it 
works for me, but may not work for you. Here is an example:

     # epurge --pretend app-arch/zip-2.3-r1 app-arch/unzip-5.42

     These are the packages that I would unmerge, in order.

     [ebuild UNMERGE] app-arch/zip-2.3-r1
     [ebuild UNMERGE] app-arch/unzip-5.42


- Zach