Italics, Underline, and Strikethrough support

[E5ten]

This switches rager to using my ransid fork and makes italics and underline support work. Fixes #8

[E5ten]

I added strikethrough support to both ransid and rager, and I installed termite to test it because my terminal doesn't support strikethrough, it worked so I saw no reason not to add it to this.

[tcr]

Checked locally on my machine and it seemed to work with my test script, I think we can merge this as-is. Thanks for the PR!

[tcr]

Okay, just discovered I'm blocked on publishing to crates.io until we can no longer rely on a git dependency. So this will have to live in git master until we can upstream the other PR, or the dependent crate is vendored. cargo install --git https://github.com/tcr/rager -f continues to work though.

[E5ten]

I will make a pull request on ransid upstream tomorrow mornin and if it isn't merged after a while I could always make a new crate I guess.