1. Special mode to search in error logs: if SEARCH_RANGE is not set,
the file is considered an error log and the search is performed
since the last CURRENT_TEST: line
2. Number of matches is printed too. "FOUND 5 /foo/ in bar".
Use greedy .* at the end of the pattern if number of matches
isn't stable. If nothing is found it's still "NOT FOUND",
not "FOUND 0".
3. SEARCH_ABORT specifies the prefix of the output.
Can be "NOT FOUND" or "FOUND" as before,
but also "FOUND 5 " if needed.
* some of these tests run just fine with InnoDB:
-> s/have_xtradb/have_innodb/
* sys_var tests did basic tests for xtradb only variables
-> remove them, they're useless anyway (sysvar_innodb does it better)
* multi_update had innodb specific tests
-> move to multi_update_innodb.test