Cause cros_workon to die rather than clobber local_manifest

Cause cros_workon to die rather than clobber local_manifest

cros_workon would clobber local edits to local_manifest in many cases
This is a quick fix to prevent it. The proper solution is to actually parse
local_manifest as an XML doc and modify the DOM. Not play tricks with grep.

BUG=chromium-os:6272
TEST=Ran cros_workon against missing local_manifest, auto-generated local_manifest, local_manifest with indented tags. local_manifest with multi-line tags and local_manifest with <remote tags.

[Mandeep Singh Baines, 2010-08-31 17:14:16]

LGTM. I'll try to have the XML parsing CL out withing the next couple of days.

[Mandeep Singh Baines, 2010-08-31 17:35:27]

LGTM. You can use -q to avoid all the >> /dev/null's.

[kliegs, 2010-08-31 17:47:19]

On 2010/08/31 17:35:27, Mandeep Singh Baines wrote:
> LGTM. You can use -q to avoid all the >> /dev/null's.

Oh I feel shame.  I knew that too and half the time I'm still dumb and do >>. 
Let me fix and resubmit

[Mandeep Singh Baines, 2010-09-01 03:42:53]

LGTM

Sorry for the delay. Was offline firefighting today.

[zbehan, 2010-09-01 03:45:15]

This is probably only temporary, before mandeep finishes his change, but
still good.

LGTM over its dead core dump.

On Tue, Aug 31, 2010 at 8:42 PM, <msb@chromium.org> wrote:

> LGTM
>
> Sorry for the delay. Was offline firefighting today.
>
>
> http://codereview.chromium.org/3227006/show
>

[kliegs, 2010-09-01 14:01:58]

Agreed this is temporary.  Its meant to prevent data loss in the interim. 
Change checked in, with luck no one ever notices it.

On 2010/09/01 03:45:15, zbehan wrote:
> This is probably only temporary, before mandeep finishes his change, but
> still good.
> 
> LGTM over its dead core dump.
> 
> On Tue, Aug 31, 2010 at 8:42 PM, <mailto:msb@chromium.org> wrote:
> 
> > LGTM
> >
> > Sorry for the delay. Was offline firefighting today.
> >
> >
> > http://codereview.chromium.org/3227006/show
> >
>