lzma tarball support

[Joshua Root]

Vincent Lefevre wrote:
> Hi,
> 
> Some packages are now distributed with lzma compression instead of bzip2,
> e.g. texinfo 4.12:
> 
>   http://ftp.gnu.org/gnu/texinfo/
> 
> Going back to gzip would be a regression, in particular there is a big
> size difference (here 2.4 MB for gzip, 1.3 MB for lzma).
> 
> What changes does a Portfile need to select lzma?

Should just be a matter of setting extract.suffix and extract.cmd 
appropriately. But it might also be nice to add a use_lzma option that 
would do that for you, which would involve adding the option in 
port1.0/portfetch.tcl as well as another case in the fix_extract_suffix 
proc, and adding another case in the extract_init proc in 
port1.0/portextract.tcl.

- Josh