rustpkg: Remove bogus .rc file
rustpkg: Change this example to show how to do a custom build
rustpkg: Don't execute the standard build logic if there is a pkg.rs
rustpkg: Add a list of rustpkg commands that should pass

This is a test file containing examples of commands that should
succeed. When we write the test runner, we will have to figure
out how to automate them.
rustpkg: Add more tests

These are examples of what *should* work, and probably don't
work yet.