Add --config-name to recursor

This adds --config-name to pdns_recursor and rec_control.
Changed s_programname to recursor as that makes the logic more like pdns_server and is useful.
The rec_control has been updated as well so we can still query the correct recursor
Improved error message for socketfile not found
filling 'ordename' and 'auth'
fix return type of snprintf

Found by Coverity Scan. Compile-tested only.
update LUABackend::setDomainMetadata signature

Found by Coverity Scan. Compile-tested only.
add error checking in exp. recursor webserver

pdns_recursor will now fail to start when it can't bind to the webserver
socket.

Fix for Coverity CID 1029992, 1029999
Remove dead sendData function

Fix for Coverity CID 1029915, which claimed dead code inside the function,
but really, nobody calls it anymore.
Fix a typo in the webserver docs
Plug leak of include-dir directory pointers

Fix for Coverity CID 1029884.
Don't overflow the sockaddr_un-provided static buffer

sun_path is a buffer with a static length. A too long socket-dir could
overflow it.

Fix for Coverity CID 1029977 & 1029978 (Recursor). While the Auth had
the same problem, there were no Coverity results for it, likely because
of the use of strncpy there.
Provide tighter bounds to HTTP first line parser in Recursor

stringtok over the entire 16k buffer is useless. Also it might make
Coverity shut up.

Tentative fix for Coverity CID 1063848.
nproxy: Add missing chdir("/") after chroot()

Also make sure that fd 0,1,2 are correctly replaced with /dev/null.
As we (might) chroot() before daemonizing, we must open /dev/null before
chroot-ing.

Reported-By: Morten Stevens
Documentation for include-dir, fixes #967
Show built-in features in --version output
Merge pull request #966 from zeha/coverity

Some fixes for Coverity
Fix for compile error introduced by 63851c6

"update LUABackend::setDomainMetadata signature" - while my updating of
the signature is great, there apparently was no compile test prior to
submitting.
Merge pull request #973 from zeha/coverity-luabackend-fixup

Fix for compile error introduced by 63851c6
 fix ringbuffer size decrease
Add NULL initialization for d_c on httpconnector
Merge pull request #975 from cmouse/coverity-20130827

Add NULL initialization for d_c on httpconnector