[Keep] keepstored index response should have an EOF marker to enable the client to detect an incomplete response.
The response size is not known when the headers are written, so (without an EOF marker) it is impossible for the client to detect the difference between "response was truncated at a newline character" and "complete response was received".Implementation:
- keepstore writes ".\n" at the end of the index response.
- data manager throws an error (more or less equivalent to "keep node unreachable"?) if it doesn't see the EOF marker.