Simplified cases where a select was used to compare variable against ''

Simplified cases where a select was used to compare variable against ''

Limited to actual bug fix, fixing a while condition
Again confirmed on Linux PPC and on AIX 5.3

Adding option --report-times
Can't collect times if test run is aborted

Added some more info in a number of fail cases
(re-commit for administrative reasons)

main.mysqltest skipped on Windows because a perl intentionally does exit(1)
Use exit(2), as exit(1) on Windows is indistinguishable from failing to
execute perl.

Added --clean-vardir to empty vardir if no failures
Also added variable $MTR_CLEAN_VARDIR

Added some more details to warning messages, this should be enough.

Added sanity check, similar to the one preventing send without reap

Trying to run perl fails, just like it does when perl is started but fails
Trap the case that perl was not found/could not be started, and skip test
Also force a restart of servers since test may already have done something
mtr now also appends path of current perl to PATH to aid mysqltest

This happens when creating new tmpdir due to too long socket path
Don't delete it if --start-and-exit, but warn user to do it.

Adds boolean flag is_int and a separete function to check for int value
Added tests to mysqltest.test

per-file comments:
  mysql-test/t/log_tables_debug.test
        This test shouldn't be run at the embedded server.

Use UNINIT_VAR workaround instead of LINT_INIT. The former can
also be used to silence false-positives in non-debug builds as
it actually does not cause new code to be generated.

Use UNINIT_VAR workaround instead of LINT_INIT. The former is
also used in non-debug builds as it doesn't cause changes.

argument of inline_mysql_mutex_init in sql_base.cc.

When initializing LOCK_dd_owns_lock_open mutex pass
correct PSI key instead of NULL value.

mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Updated test results after adding P_S instrumentation
  for LOCK_dd_owns_lock_open.
sql/sql_base.cc:
  When initializing LOCK_dd_owns_lock_open mutex pass
  correct PSI key instead of NULL value.