Merge pull request #30 from novikane/master

streamlined tar options to include xz and lzma as requested by the todo
Update TODO

tar xz and lzma added thanks to Novikane
created additional tree_type for /usr/portage[/packages] directory
tar file and utilizing emerge's --usepkg switch to take advantage
of pre-built portage-based binary packages
Merge remote-tracking branch 'upstream/master'