Make sure the repo is initialised

app.Init() now returns an error when the repository is not initialised
for SalsaFlow. This works fine since the only place where this could
explode is in repo init itself, but there the error is ignoted, so no
circular errors.

Change-Id: 1fb2f029f4
repo init: Check the git version being used

Putting the check into repo init, which is run only once, because it is
not expected that the user would install the right git version and then
downgraded again after initialising the repository.

Change-Id: 9c121b2c28
Story-Id: SF-13
config: Make sure the local config is committed

Do not proceed further with config loading in case the local
configuration file has some uncommitted changes. This is to prevent
people from changing the local config file and forgetting to commit.

Change-Id: 665647b5e1
Story-Id: SF-14
wip

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