Update to add keyword "SCHEMA" and "SCHEMAS". Small test case was added too.

sql/lex.h:
  Update to add compatibility keyword "SCHEMA"

mysql-test/r/schema.result

+create schema foo;
+show create schema foo;
+Database	Create Database
+foo	CREATE DATABASE `foo` /*!40100 DEFAULT CHARACTER SET latin1 */
+show schemas;
+Database
+foo
+mysql
+test
+drop schema foo;

mysql-test/t/schema.test

+#
+# Just a couple of tests to make sure that schema works.
+#
+
+create schema foo;
+show create schema foo;
+show schemas;
+drop schema foo;

sql/lex.h

@@ -397,6 +397,8 @@ static SYMBOL symbols[] = {
   { "ROW_FORMAT",	SYM(ROW_FORMAT_SYM)},
   { "RTREE",		SYM(RTREE_SYM)},
   { "SAVEPOINT",	SYM(SAVEPOINT_SYM)},
+  { "SCHEMA",		SYM(DATABASE)},
+  { "SCHEMAS",          SYM(DATABASES)},
   { "SECOND",		SYM(SECOND_SYM)},
   { "SECOND_MICROSECOND", SYM(SECOND_MICROSECOND_SYM)},
   { "SECURITY",         SYM(SECURITY_SYM)},