Made some bridging API calls void. Some bridging comments updated.

git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@379753 f38db490-d61c-443f-a65b-d21fe96a405b
Extract common bridging code into bridge_stop() and bridge_force_out_all().

git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@379776 f38db490-d61c-443f-a65b-d21fe96a405b
Better protect bridge_channel state from other threads.

git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@379789 f38db490-d61c-443f-a65b-d21fe96a405b
Update init.d scripts to handle stderr; readd splash screen for remote consoles

When r376428 was commited to re-order start up sequences to be more tolerant of
forking with thread primitives, a few items were changed that caused changes
in behavior on some distros. This includes:
 * Not displaying the splash screen on a remote console.
 * Displaying an error message on stderr when a remote console cannot connect
   to a running instance of Asterisk.

In the first case, the splash screen was re-added (thanks to Michael L. Young).
In the second case, the various init.d scripts were modified to pipe stderr
to /dev/null, as the error message is useful - if you execute a remote
console or a remote console command execution and it fail, it should tell
you. Note that the error message was always present, it just failed to be
printed prior to r376428.

Much thanks to the folks who quickly reported this problem, provided solutions,
and promptly tested the various init.d scripts on a variety of distros.

(closes issue ASTERISK-20945)
Reported by: Warren Selby
Tested by: Michael L. Young, Jamuel Starkey, kaldemar, Danny Nicholas, mjordan
patches:
  asterisk-20945-remote-intro-msg.diff uploaded by elguero (license 5026)
  ASTERISK-20945-1.8-mjordan.diff uploaded by mjordan (license 6283)
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Merged revisions 379760 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 379777 from http://svn.asterisk.org/svn/asterisk/branches/10
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Merged revisions 379790 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@379791 f38db490-d61c-443f-a65b-d21fe96a405b