Fixed wrong allocation that could cause buffer overrun when using join cache


myisam/mi_open.c:
  Fixed indentation
mysql-test/r/lowercase_table2.result:
  Drop tables and databases used in the test
mysql-test/t/lowercase_table2.test:
  Drop tables and databases used in the test
mysys/my_fopen.c:
  Cleanup of comments and parameter names
  Simple optimization
  Removed compiler warnings
sql/field.cc:
  Fixed wrong allocation that could cause buffer overrun
sql/mysqld.cc:
  Removed not needed code
sql/set_var.cc:
  Simply code
sql/sql_select.cc:
  Use int2store/int2korr to store length of cached VARCHAR fields
  (Not dependent on type and faster code as we avoid one possible call)