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 a typo in the webserver docs
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
 fix ringbuffer size decrease
rfc2136handler: Close socket when write fails

Fix for Coverity CID 1066217.
Fix zone2{sql,json} exit codes

To be consistent with general practice, fix zone2{sql,json} to exit
with:
 * 0 on success
 * 1 on error

This also moves the catch block after the last line of main, so a
"theoretically" possible exception in ::arg().mustDo would get caught.
(Also, one level less of indent!)
Fix coverity CID 1066169
Merge pull request #971 from cmouse/include-dir-doc

Documentation for include-dir, fixes #967
Merge pull request #951 from cyclops1982/935

Add --config-name to recursor
update pidfile name after b842fd64c37181881a74959add76c5538fd687ea
Merge pull request #952 from mind04/doc

filling 'ordename' and 'auth'
Merge pull request #968 from zeha/docs-typo

Fix a typo in the webserver docs
Merge pull request #970 from zeha/nproxy-chroot-chdir

nproxy: Add missing chdir("/") after chroot()
drop visual studio dsp files, thanks @cmouse
pid file with pdns_ prefix.
Also controlsocket file with pdns_ prefix.