"stg import --reject" is broken

[dtor]

According to the documentation "stg import --reject" is supposed to add an empty patch to the stack. It also says that failed diff will be saved as .stgit-failed which does not make much sense and is different from how old versions of stg behaved (i.e. apply what it can to the working tree and leave the rest as *.rej files). It also contradicts explanation to the "--reject" option which says that it will "leave rejected hunks in .rej files".

Unfortunately the current behavior is to partially apply to the work tree and leave .rej (which is good), but no commit is created.