Add *sort_buffer_size variables.
Arrange for the test infrastructure to undo any global variable changes on the underlying mysql instance.
Merge branch 'master' into kanzaros_eh

Conflicts:
	tesora-dve-core/src/main/java/com/tesora/dve/variables/KnownVariables.java
PE-1587, PE-1589, PE-1590 - Added global system variables.
PE-1591 - Added unit test.
Lookup EnumVariableValues by toString() rather than name()
implementation.
Added ARCHIVE and CSV engines to supported storage engines.
Marked BLACKHOLE, PERFORMANCE_SCHEMA and FEDERATED as unsupported.
Extended unit testing for storage engines.
Reebonz upgrade issue: LONG_PLAN_STEP_TIME variable should be
floating-pont.
PE-1599, PE-1600 - Fixed unit test for SHOW ENGINES.
Variables - use correct scope for some of the recently added global
system variables.
PE-1593 - When you refer to a system variable in an expression as
@@var_name (that is, when you do not specify @@global. or @@session.),
MySQL returns the session value if it exists and the global value
otherwise. (This differs from SET @@var_name = value, which always
refers to the session value.)
Use EnumValueConverter<MySQLTransactionIsolation> to handle the
"tx_isolation" variable.

Make sure to quote the variable values on after-test reset.
Make quoting type safer...
Added system global 'have_partitioning' variable. The feture is planned,
but currently not supported, so return 'NO'.
Add result set metadata fixes, specifically proper computation of column aliases.
Instrument projection parsing to find derived column boundaries and store it in source
location information.   During projection metadata computation, arrange to use such
source location in building derived column aliases.

After finally fixing this (after at least a year), I decided to uncategorically turn
on metadata comparison for mirror tests, which yielded several more issues:
+ The information_schema was persisted in the wrong case.  Fix this, and arrange
  for a case insensitive lookup.
+ At least part of the info schema presented the wrong column types.  Fix these
  as I found them.
+ Add another infoschema upgrade.

Still todo:
+ Figure out what to do about ignoreMD in ComparisonOptions.
PE-1603 - Added 'timestamp' session variable. Contains the current
system (DVE) time if set to DEFAULT or 0. Affects the value returned by
NOW(). Can be overriden by 'dve_repl_slave_timestamp' if set to a
non-zero value.
PE-1603 - Added isNumeric() method to ValueMetadata. TRUE for numeric
variables which values must not be quoted in SET stmts.
Merge branch 'master' into kanzaros_eh
Make sure that we always use the alias name when building temp tables.
Handle case where stmt is across multiple lines.
Fix DVE-1592.
+ Rearrange column modifier parsing slightly to handle inline key defs:
  - 'PRIMARY KEY'
  - 'UNIQUE KEY'
  - 'UNIQUE'
  - 'KEY'
+ In transutils clean up the case where we may have UNIQUE, KEY.

Also, make sure that we clear any parsing related values at the appropriate time,
specifically, lose the reference to the input sql.