Typo.
Fixed the licensing mess.

Currently we have a mess of: GPLv2 + LGPLv2 + GPLv3. I've re-licensed all my
code to GPLv3+. The remaining code has been left untouched, because it follows
the LGPLv2+ license (therefore it's ok that they co-exist). I've also included
a `LICENSE` file, which is mandatory.
Added a note on the README file about the coding style being used.
Apparently it's better to allocate the Parser on the heap.

This way we avoid some random crashes.
rails: don't assert if quickopen is not loaded.

This way we avoid crashing when using the `duchainify` tool.