gpg: accept '--edit' like other commands creating new changeset After this patch, users can invoke editor for the commit message by '--edit' option regardless of '--message'.

memfilectx: add a size method This method is needed to have memfilectx behave like the other file contexts. We can't just inherit this method because each file context has different behavior: filectx reads from the filelog, and workingfilectx reads from the disk. Therefore, we define memfilectx to return the size of the data in memory.