pget local->local should check the source control branch for uncommitted changes

[Alexander Belchenko]

See question https://answers.launchpad.net/bzr-scmproj/+question/60456
To improve user experience we should check that project.cfg is actually committed in the source project (for local->local cloning) and emit warning if it's changed. See below quote from discussion with Geoff.

Geoff Bache пишет:
> Geoff Bache is still having a problem:
> Well, it didn't fail the same way as before, but now when I do "bzr
> pget" I get a new project.cfg file which is the same as the initial one
> (i.e. it isn't a copy of the one at the place where I did pget from).
> Then bzr pco does nothing, which isn't surprising given the above I
> suppose.

I'm sure this is because lacks of the documentation. The scmproj is pretty new,
as you see.

> My project.cfg file:
>
> ## describe each component in subsequent sections, e.g.:
> [component generic]
> RELPATH = .
> BRANCH_URL = /home/geoff/bzrtest/scmproj
>
> ## describe each component in subsequent sections, e.g.:
> [component site]
> RELPATH = dir2
> BRANCH_URL = /home/geoff/bzrtest/scmproj/dir2

It seems this is not clear in the documentation, but the .scmproj control dir
has actually separate bzr branch inside. And you need to commit your new
config before you do successful pget.