Fix AGI exec Park to honor the Park application parameters.

The fix for ASTERISK-12715 and ASTERISK-12685 added a check for the Park
application because the channel needed to be masqueraded to prevent a
crash.  Since the Park application now always masquerades the channel into
the parking lot, the special check is no longer needed.  The fix also
resulted in AGI exec Park attempting to double park the call and not honor
the Park application parameters.

* Removed no longer necessary call to ast_masq_park_call() by AGI exec for
the Park application.  (Reverts -r146923)

* Fix Park application to only return 0 or -1.  The AGI exec Park was
causing broken pipe error messages because the Park application returned 1
on successful park.

(closes issue ASTERISK-18737)
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Merged revisions 341717 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 341718 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@341719 65c4cc65-6c06-0410-ace0-fbb531ad65f3