MDEV-6846: Test tokudb_mariadb.mdev6657 fails in buildbot

Update the testcase so it is still meaningful when fix for MDEV-6657
is present in the code.
MDEV-6702: analyze_stmt test fails in --embedded 10.1

Provide Protocol_discard::storeXXX functions for all kinds
of objects that could be stored. Failure to so would caused
crashes in embedded server which attempted to collect the
stored info.

This also reduces the amount of copy operations for non-embedded
case.
followup changes to timeout commit

* fix debian patch
* update the copyright
* rename include guards to follow conventions
* restore incorectly deleted test file, add clarification in a comment
* capitalize the first letter of the status variable
cleanup: simplify the usage of WSREP_FORMAT macro
cleanup: galera misc cleanups

also disable galera-specific output in mysql_tzinfo_to_sql,
it'll be enabled later.
Plugin API: increase SHOW_VAR_FUNC_BUFF_SIZE for 64-bit CPUs

instead of having it 1K everywhere, make it 1K on 32-bit and 2K on 64-bit.
As the latter has larger pointers (and larger sizeof(SHOW_VAR),
it needs a larger buffer to store the same amount of SHOW_VARs
cleanup: case SQLCOM_CALL

move SP invocation code out of the huge switch in mysql_execute_command
cleanup: use null_lex_str where appropriate
cleanup: public Item_param::get_settable_routine_parameter()

make Item_param::get_settable_routine_parameter() public, because it's
public in the parent Item class and all other Item descendants too
cleanup: rename List<> methods

prepand() -> prepend()
concat() -> append()
cleanup: inherit from Sql_alloc

instead of copy-pasting its methods into a new class
cleanup: class my_var

* split my_var class in three - base my_var and two descencants, move
  properties into descendants, remove if(), create a virtual method instead
* factor out the common code in the select_var_ident parser rule
cleanup: param_marker rule in the parser

preserve the Item_param type of the param_marker in the parser,
don't upcast cast it to Item
cleanup sql_yacc.yy: s/YYABORT/MYSQL_YYABORT/
cleanup sql_yacc: introduce opt_not rule, combine otherwise duplicate rules
cleanup sql_yacc.yy: remove duplicate code in opt_union rule
cleanup sql_yacc.yy: rename rules for loops with and without label to follow BEGIN...END rule naming
cleanup sql_yacc.yy: factor out duplicate code in PROCEDURE/FUNCTION/TRIGGER/EVENT grammar
cleanup sql_yacc.yy: reduce code duplication in rules for BEGIN...END with and without label
cleanup sql_yacc.yy: s/IF/IF_SYM/