Added new syntax ALTER TABLE t1 REMOVE PARTITIONING,
changed semantics of ALTER TABLE t1 ENGINE=X; to not remove partitioning
Fix a number of mix engine bugs in partitioning


mysql-test/r/ndb_partition_key.result:
  Added a number of new test cases
mysql-test/r/partition.result:
  Added a number of new test cases
mysql-test/t/ndb_partition_key.test:
  Added a number of new test cases
mysql-test/t/partition.test:
  Added a number of new test cases
sql/lex.h:
  REMOVE and PARTITIONING added as keywords in parser
sql/sql_lex.h:
  Added flag to alter_info flag
sql/sql_partition.cc:
  Fixes for the new syntax, changes of the current semantics of the syntax.
  Fixes for errors in handling mixes of table handlers in partitioning syntax
  for ALTER TABLE
sql/sql_table.cc:
  Bug fix
sql/sql_yacc.yy:
  New syntax for REMOVE PARTITIONING