Add t0000-basic.sh as sharness.t from upstream@6fedcd8188

Source: https://raw.github.com/git/git/master/t/t0000-basic.sh
Remove Git-specific stuff from sharness.t
Make test number come first in 'not ok $count - $message'

See https://github.com/git/git/commit/5e5c006eb713b785c6761c32b907e02abc277f9a
Paint known breakages in yellow and unexpectedly fixed known breakages in bold red

https://github.com/git/git/commit/b73d9a2363beedd59c212b5aa6b9db2977c38b2b
https://github.com/git/git/commit/e8e5195573bc0f314ccc288f7d009b47e4440760