rename "rxhdrs" to "rxreqhdrs" and add "rxresphdrs"
There is no `y' (year) suffix
More spelling fixes
A few more spelling fixes
Spotted while looking for 1449:

Make sure we do not send a regular "end-chunk" to the
client if the streaming fetch fails.
Add a test-case to check that vcl_backend_error{} objects can be cached.
Fix a race when we Unbusy and abandonned oc which has no object.

Fixes	#1449
Fix URL
Typos and itsos
Don't unbusy failed objects, it is pointless and introduces a race.
Reserve h key for a future help screen

Move showing of debug counters from 'h' key to 'd' inside a running
varnishstat.
Helpful pointers for future contributors

Mostly an attempt at pointing people that send pull requests on Github
in the right direction.
Small example on how to do synthetic responses
Dump some info on fetch_objcore during panics
Try to close the #1449 race definitively.
Comment out an assert to get jenkins happier
Add varnishhist
Typo in makefile.phk
Comment out another busy check
White space fix