Revert "Set GITORIOUS_REPOSITORY_ID when locally pushing to merge req refs"

This is not needed because as of now both pre and post-receive hooks
don't do anything for local pushes. It is responsibility of the code
that makes a local push to do any needed post-push processing.

This reverts commit 0b18f288bc210a1ade19427ea1b9e5f14bba64ea.
Don't force Rails.root/data/hooks -> repositories_root/.hooks symlink

Hooks have been removed from this repository and place in
https://gitorious.org/gitorious/gitorious-proto . Symlinking of hooks
dir into repositories_root/.hooks is a responsibility of the
installation script.