Restore Dial, Queue, and FollowMe 'I' option support.

The Dial, Queue, and FollowMe applications need to inhibit the bridging
initial connected line exchange in order to support the 'I' option.

* Replaced the pass_reference flag on ast_bridge_join() with a flags
parameter to pass other flags defined by enum ast_bridge_join_flags.

* Replaced the independent flag on ast_bridge_impart() with a flags
parameter to pass other flags defined by enum ast_bridge_impart_flags.

* Since the Dial, Queue, and FollowMe applications are now the only
callers of ast_bridge_call() and ast_bridge_call_with_flags(), changed the
calling contract to require the initial COLP exchange to already have been
done by the caller.

* Made all callers of ast_bridge_impart() check the return value.  It is
important.  As a precaution, I also made the compiler complain now if it
is not checked.

* Did some cleanup in parking_tests.c as a result of checking the
ast_bridge_impart() return value.

An independent, but associated change is:
* Reduce stack usage in ast_indicate_data() and add a dropping redundant
connected line verbose message.

(closes issue ASTERISK-22072)
Reported by: Joshua Colp

Review: https://reviewboard.asterisk.org/r/2845/
........

Merged revisions 399136 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@399138 f38db490-d61c-443f-a65b-d21fe96a405b