MDEV-7563 Support CHECK constraint as in (or close to) SQL Standard

MDEV-10134 Add full support for DEFAULT

- Added support for using tables with MySQL 5.7 virtual fields,
  including MySQL 5.7 syntax
- Better error messages also for old cases
- CREATE ... SELECT now also updates timestamp columns
- Blob can now have default values
- Added new system variable "check_constraint_checks", to turn of
  CHECK constraint checking if needed.
- Removed some engine independent tests in suite vcol to only test myisam
- Moved some tests from 'include' to 't'. Should some day be done for all tests.
- FRM version increased to 11 if one uses virtual fields or constraints
- Changed to use a bitmap to check if a field has got a value, instead of
  setting HAS_EXPLICIT_VALUE bit in field flags
- Expressions can now be up to 65K in total
- Ensure we are not refering to uninitialized fields when handling virtual fields or defaults
- Changed check_vcol_func_processor() to return a bitmap of used types
- Had to change some functions that calculated cached value in fix_fields to do
  this in val() or getdate() instead.
- store_now_in_TIME() now takes a THD argument
- fill_record() now updates default values
- Add a lookahead for NOT NULL, to be able to handle DEFAULT 1+1 NOT NULL
- Automatically generate a name for constraints that doesn't have a name
- Added support for ALTER TABLE DROP CONSTRAINT
- Ensure that partition functions register virtual fields used. This fixes
  some bugs when using virtual fields in a partitioning function

mysql-test/extra/rpl_tests/rpl_extra_col_master.test

@@ -126,7 +126,7 @@ SELECT f1,f2,f3,f4,f5,f6,f7,f8,f9,
 
 --disable_query_log
 call mtr.add_suppression("Slave SQL.*Table definition on master and slave does not match: Column 2 type mismatch.* 1535");
-call mtr.add_suppression("Slave.*Can.t DROP .c7.; check that column.key exists.* error.* 1091");
+call mtr.add_suppression("Slave.*Can.t DROP .c7.; check that .* exists.* error.* 1091");
 call mtr.add_suppression("Slave.*Unknown column .c7. in .t15.* error.* 1054");
 call mtr.add_suppression("Slave.*Key column .c6. doesn.t exist in table.* error.* 1072");
 call mtr.add_suppression("Slave SQL.*Column 2 of table .test.t1.. cannot be converted from type.* error.* 1677");