Add void ./configure options

This commit adds a function to the ./configure script and uses it to specify several options which should be ignored when given to configure by callers, such as Ubuntu's debhelper.

Rather than ignore all otherwise unusable options given, it seems more sane to list the ones we want to drop, so I've done that. I've listed only those I had to for [my Ubuntu PPA](https://launchpad.net/~kevincantu/+archive/rust/) to build correctly for Rust 0.6.


Kevin