Split astobj2.c into more maintainable components.

Split astobj2.c into the following files to improve maintainability.

astobj2.c - object primitives, object primitive misc and initialization code.
astobj2_private.h - internal object declarations needed by the containers.
astobj2_container.c - generic conainer and container misc code.
astobj2_container_hash.c - hash container specific code.
astobj2_container_rbtree.c - rbtree container specific code.
astobj2_container_private.h - generic container definitions and rtti prototypes.

https://reviewboard.asterisk.org/r/3576/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@415317 f38db490-d61c-443f-a65b-d21fe96a405b
Update utils/Makefile so refcounter compiles post astobj2 split.

utils/refcounter was removed from trunk so this is a 12-only patch
to keep refcounter from failing to build.

https://reviewboard.asterisk.org/r/3576/


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@415318 f38db490-d61c-443f-a65b-d21fe96a405b