Remove lock inside verify_environment, caller has the protection. This is to
avoid self deadlock
Fixes for LDT Lstack, and to move to the new LDT API for Lstack.
The new LDT API will allow LDT functions to be called from both
external sources (i.e. applications) and internal sources (UDFs).
Merge branch 'master' of github.com:citrusleaf/aerospike-mod-lua