Added support for Allow-Address-Pairs feature

Added support for feature called Allow-Address-Pairs introduced in
Ie73b3886c5be8e1fc4ade86a0cfb854267f345ac

Change-Id: I29f3555e55df6ad6ba41e7ec503cd05ad2a162df
Implements: blueprint allowed-address-pairs
Remove param explode_nested from doc

Remove param explode_nested from method resource_to_template document
since it does not exist in parameters.

Change-Id: I0ef14319bf6e39bb59a3d1753fc57bdb7698fe38
Merge "Added support for Allow-Address-Pairs feature"
Merge "Remove param explode_nested from doc"