.gitcheck: re-write entirely. force global config.

the way the old script worked was extremely hacky

it's cleaner just to make the user configure git

i haven't used anything from the old .gitcheck script,
which is now deleted. i completely re-wrote this, in
a much simpler way.

this is less maintenance now, when things change in
the upstream projects. coreboot makes heavy use of git
within its build system

Signed-off-by: Leah Rowe <leah@libreboot.org>

resources/git/revisions

@@ -2,9 +2,8 @@
 # for various git projects used by lbmk.
 # Project name is enclosed by curly braces '{}' information about the
 # project relevant to lbmk is stored between the subsequent curly
-# braces. This file is used by the gitcheck script as well as the
-# fetch script. Each entry must include: revision 'rev', location
-# 'loc', and the git url 'url'. Bkup_url is optional.
+# braces. This file is used by the fetch script. Each entry must include:
+# revision 'rev', 'location', 'loc', and the git url 'url'. Optional: 'bkup_url'
 
 {coreboot}{
 	rev: HEAD