Adds support for concurrent indexing in PostgreSQL adapter

Adds support for algorithm option in MySQL indexes
Moves USING and algorithm options upstream

The syntax is still specific to the Adapter, so the actual executed string happens
in the corresponding adapter
Checks :algorithm argument for valid values
Merge pull request #9923 from danmcclain/psql-concurrent-indexes

Adds support for concurrent indexing in PostgreSQL adapter
Fixed timezone mapping of Ulaanbaatar.
Merge pull request #9937 from zolzaya/master

Asia/Ulaanbaatar is incorrect mapping

Fixes #9936