This adds an EVAL_SUB function, which is similar to the existing
EVAL_EXTEN function but significantly more powerful, as it allows
executing arbitrary dialplan and capturing its return value as
the function's output. While EVAL_EXTEN should be preferred if it
is possible to use it, EVAL_SUB can be used in a wider variety
of cases and allows arbitrary computation to be performed in
a dialplan function call, leveraging the dialplan.
Resolves: #951
(cherry picked from commit b01a3cfdcb)
This adds the EVAL_EXTEN function, which may be used to retrieve
the variable-substituted data at any extension.
ASTERISK-29486
Change-Id: Iad81019689674c9f4ac77d235f5d7234adbb1432
