repo init: Require Git version 1.9 at least

The reparator we need was added in version 1.8.5.4, so let's just require 1.9.0
to save some parsing and some extra code.

Change-Id: 37df95cde7
wip

Change-Id: 06c9d9982e
Story-Id: SF-6
wip

Change-Id: 6be6e13ae0
Story-Id: SF-6
wip

Change-Id: f961f519a5
Story-Id: SF-6
wip

Change-Id: d3a353bf2c
Story-Id: SF-6
wip

Change-Id: 85fa888ed4
Story-Id: SF-6
wip

Change-Id: 5e2c30383d
Story-Id: SF-6
wip

Change-Id: 169450a245
Story-Id: SF-6
wip

Change-Id: 91ff7bfb64
Story-Id: SF-6
wip

Change-Id: 34b01114be
Story-Id: SF-6
wip

Change-Id: a267f29462
Story-Id: SF-6
wip

Change-Id: f404a0cefb
Story-Id: SF-6