Revert "Merge branch 'jc/graduate-remote-hg-bzr' (early part)"

Instead of showing a warning and working as before, fail and show
the message and force immediate upgrade from their upstream
repositories when these tools are run, per request from their
primary author.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
RelNotes/2.0.0.txt: Fix several grammar issues, notably a lack of hyphens, double quotes, or articles

Signed-off-by: Jason St. John <jstjohn@purdue.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git 2.0-rc4

Signed-off-by: Junio C Hamano <gitster@pobox.com>