Merge changes I56f29eac,Ic7530d44

* changes:
  Fixed usages of memset(..0..) to use Calloc/init'er
  Added OCCalloc functionality and Fixed Malloc Tests

diff --cc resource/csdk/occoap/src/occoap.c
Simple merge

diff --cc resource/csdk/ocsocket/src/ocsocket.c
Simple merge

diff --cc resource/csdk/stack/include/internal/ocstackinternal.h
Simple merge

diff --cc resource/csdk/stack/include/ocstack.h
Simple merge

diff --cc resource/csdk/stack/src/occollection.c
Simple merge

diff --cc resource/csdk/stack/src/ocobserve.c
Simple merge

diff --cc resource/csdk/stack/src/ocserverrequest.c
Simple merge

diff --cc resource/csdk/stack/src/ocstack.c
Simple merge