Fix:
1. Represenation of map and list in json format by as_val_tostring
2. Msgpack is now handling signed data properly.
Merge pull request #3 from citrusleaf/msgpk_signed_bug

Fix:
Fixing handling of postitve integers while unpacking msgpack.
Bug: Some range of positive integers got bugged while fixing msgpack
unpacking of negative integers.
Added as_vector.
Add as_strncpy().
Add more comments to as_strncpy().
Added shash_deleteall function for xdr_in_asd
Added declaration of shash_deletall in header file.
copyright update
Fix to as_arraylist to validate legal area of list before calling destroy on old value.
Jira AER-2432.