TokuDB issues when merging with MariaDB

[Sergei Golubchik]

I've merged TokuDB from 5.6.28-76.1 into MariaDB. There were few Here's everything I've fixed. There's also a larger one that I'll report separately.

1. changes under TOKU_INCLUDE_OPTION_STRUCTS — the code needed to be moved around a bit, because HA_TOPTION_SYSVAR() needed to be in the same namespace as sysvars, and it also needed to see the definition of struct ha_table_option_struct. There was also one typo to fix.

2. changes under HA_TOKUDB_HAS_THD_PROGRESS — that's easy, one forgotten s/rows/row_count()/

3. functions disable_slow_update() and disable_slow_upsert() were not under #if TOKU_INCLUDE_UPSERT

4. ::my_realloc(...) was missing MY_ALLOW_ZERO_PTR flag (safe to do both for MySQL and MariaDB)

5. a couple of other minor things under #ifdef MARIA_PLUGIN_INTERFACE_VERSION, see the patch

[George Ormond Lorch III (gl-az)]

https://tokutek.atlassian.net/browse/DB-967

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-3379