bug#17380: grep -C 0 could also give separators

[Paul Eggert]

Norihiro Tanaka wrote:
> The argument that a separater should also be output for zero might be reasonable

It sounds reasonable to me, too.  Unfortunately that patch did not work 
for me.  Also, the change should be documented in NEWS, and the 
documentation updated, and a test case added.  I installed the attached 
patches.

0001-grep-A-0-B-0-C-0-now-output-a-separator.patch
Description: Text document

0002-tests-add-test-case-for-C-0-change.patch
Description: Text document