[MERGE][0.14] Allow 'bzr push' to push onto existing dir

[Martin Pool]

Martin Pool has voted +1 (conditional).
Status is now: Conditionally approved
Comment:
I think this is reasonable.  It will improve the case where people are 
pushing to a half-created branch.

I think it would be appropriate to give more feedback about what is 
happening in some of these cases:

   Creating new branch and repository at %s
   Creating new branch within repository at %s

+                     Option('use-existing',
+                            help='By default push will fail if the 
target'
+                                 ' directory exists, but does not 
already'
+                                 ' have a control directory. This flag 
will'
+                                 ' allow push to proceed.'),
+                     ]

And I wonder if it would be better to just go ahead and push if the 
destination is an *empty* existing directory? -- but that is a separate 
matter.

I think this would be ok for 0.14.  You should also add a NEWS note that 
they were closed.

How about instead saying:

   Create a new bzr control directory within an existing directory.

+            # XXX: Figure out what to do other than complain.
+            raise errors.BzrCommandError("At %s you have a valid .bzr 
control"
+                " directory. But we could not find a valid repository 
or"
+                " branch associated with it. This is an unsupported"
+                " configuration. Please move the target directory out 
of the"
+                " way and try again."

(You shouldn't start a sentence with 'but' in formal English.)

   %s contains a .bzr control directory, but not a branch or repository. 
This is an unsupported etc etc

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C45A3F5DA.6040007%40arbash-meinel.com%3E