Merge branch 'jc/maint-blame-minimal' into maint

"git blame" started missing quite a few changes from the origin since we
stopped using the diff minimalization by default in v1.7.2 era.

Teach "--minimal" option to "git blame" to work around this regression.

* jc/maint-blame-minimal:
blame: accept --need-minimal

diff --cc builtin/blame.c
Simple merge