BUG#11316 mysqltest, problems when assigning value with '#' to $variable

- Fixed problem, only detect comment if the # is on start of line AND starting line of the current command.
 - Wrote tests for most of the mysqltest commands, added stricter checking of correct syntax.


client/mysqltest.c:
  Updated mysql test to do stricter checking of syntax. For example when the number 
  of arguments to a command is known, everything else is "junk" => die. 
  Better checking of argument types.
  Added better debug printouts.
  Added improved printouts when wrong syntax is detected.
  Fix two bugs where mysqltest could not detect end of comamnd properly, as described in bug#11316
  Fix segfault when performing too many source commands.
  Fix segfault when doing too many while loop levels.
  Add printout of line number in die
  Remove lineno and \n in all strings passed to die function.
  Decrese BLOCK_STACK_DEPTH from 32 to 16, does any test use more than 1 level?
mysql-test/mysql-test-run.pl:
  export MYSQL_TEST environment variable, used from msyqltest.test
mysql-test/mysql-test-run.sh:
  export MYSQL_TEST environment variable, used from msyqltest.test
mysql-test/r/mysqltest.result:
  Updated test results
mysql-test/r/rpl_flush_log_loop.result:
  Updated test result.
  Approved by lars
mysql-test/t/innodb-deadlock.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/innodb-lock.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/mysqltest.test:
  Add several new tests  for mysqltest.
  Foxus on detecting wrong syntax in test files.
  Use exec with expected error to execute test scripts that will kill mysqltest
  Change some negative test that were previously commented out to use the above method.
mysql-test/t/ndb_autodiscover2.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/rpl_change_master.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/rpl_deadlock.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/rpl_drop_temp.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/rpl_flush_log_loop.test:
  Fix after detecting wrong syntax, missing ;
  Discussed with lars.
mysql-test/t/rpl_insert_id.test:
  Missing ;
mysql-test/t/rpl_rotate_logs.test:
  Correct wrong syntax
  Superfluos ;
mysql-test/t/rpl_until.test:
  Missing delimiter
mysql-test/include/mysqltest_while.inc:
  New file to test too many while levels

mysql-test/t/rpl_insert_id.test

@@ -4,7 +4,7 @@
 # We also check how the foreign_key_check variable is replicated
 
 source include/master-slave.inc;
-source include/have_innodb.inc
+source include/have_innodb.inc;
 connection master;
 create table t1(a int auto_increment, key(a));
 create table t2(b int auto_increment, c int, key(b));