* move shell completion scripts to where can be auto picked up

Let's use switching new remote as opportunity to put shell completion
scripts to where they should be and avoid git conflict during the process.

* add Library/Formula and Library/Aliases symlinks

Formulae and Aliases has been relocated to homebrew/core tap.
The symlinks are pointed to new location to keep backward compatibility.

* remove formula_renames and tap_migrations

They have been replaced by the json files in the core tap.

* update: set new remote

* bump Homebrew version to 0.9.9