adb import

As well as adding the necessary methods, a few other changes to the adb
remote:

* Use ".annextmp" extension for temp files, to avoid conflict with other
  temp files.
* Stop using "echo $?" to get exit status of command inside adb.
  There were two problems; first the "echo" just before it meant it was
  always 0! And secondly, it seems kind of random on my phone whether it's
  1 or 0, not dependant on whether the command seems to have succeeded.

doc/todo/adb_import.mdwn

@@ -31,4 +31,7 @@ Alternatively, the documentation could tell the user to avoid modifying files
 on their android device while git-annex is exporting to it, or to instead
 only ever modify files on the android device, and import from it, but not
 export any changes to it. (Or some combination of those 
-for different subdirectories on it.)
+for different subdirectories on it.) But it seems like this won't be
+necessary.
+
+> [[done]] --[[Joey]]