transfers: Fix bug setting both BLINDTRANSFER and ATTENDEDTRANSFER

The ast_bridge_set_transfer_variables function is supposed to wipe whichever
variable isn't being set. Instead it was setting both to the new value.  Oops.

(issue AFS-24)


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@403957 f38db490-d61c-443f-a65b-d21fe96a405b
security: Inhibit execution of privilege escalating functions

This patch allows individual dialplan functions to be marked as
'dangerous', to inhibit their execution from external sources.

A 'dangerous' function is one which results in a privilege escalation.
For example, if one were to read the channel variable SHELL(rm -rf /)
Bad Things(TM) could happen; even if the external source has only read
permissions.

Execution from external sources may be enabled by setting
'live_dangerously' to 'yes' in the [options] section of asterisk.conf.
Although doing so is not recommended.

Also, the ABI was changed to something more reasonable, since Asterisk
12 does not yet have a public release.

(closes issue ASTERISK-22905)
Review: http://reviewboard.digium.internal/r/432/
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Merged revisions 403913 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 403917 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@403959 f38db490-d61c-443f-a65b-d21fe96a405b