Correct installation to follow standards
Add the standard Rust Apache/MIT license

This copies the same Apache and MIT license files from the rust-lang/rust
repository to the cargo repository. It notable retains the same copyright line
as the rust repository:

    Copyright (c) 2014 The Rust Project Developers

The COPYRIGHT file from the rust repository was not copied over as it looked
like it mainly contained information about third party dependencies, which cargo
does not have yet.

The wording at the end of the rust repository's README.md was also copied over
to cargo's README.md with tweaks to not mention COPYRIGHT and third-party BSD
licenses.

Closes #34
Merge pull request #50 from alexcrichton/license

Add the standard Rust Apache/MIT license
Removes vagrant files from project

Fixes #40
Merge pull request #48 from gilles-leblanc/issue40

Adds .vagrant files to .gitignore
Merge pull request #49 from o11c/install-paths

Correct installation to follow standards
Update README.md
Add support for branch/tag/rev options
Rename make distclean -> clean-all
Use correct path separator on windows
Append .exe to commands for windows
fix some windows tests