#180 avoid thd_proc_info pointing to invalid info (like when a function sets proc info with a local variable and then returns)

#177 disable inline alter table drop default, add key, drop key, rename column when null bytes changed

Tokutek/mysql56#54 fix to tokudb::external_lock for the alter table assert bug, plus a rewrite of the tokudb debug tracing

Tokutek/mysql56#71 run mysql suite tokudb.add_index without tokudb as the default storage engine (fix hot_create_unique_index.result)