On an INSERT into an updatable but non-insertable view an error message was
issued stating the view being not updatable. This can lead to a confusion of a
user.

A new error message is introduced. Is is showed when a user tries to insert
into a non-insertable view.


sql/sql_base.cc:
  Fixed bug#5505: Wrong error message on INSERT into a view
  The update_non_unique_table_error() function now issues proper
  error for an INSERT.
sql/sql_insert.cc:
  Fixed bug#5505: Wrong error message on INSERT into a view
  Issue the ER_NON_INSERTABLE_TABLE error instead of the 
  ER_NON_UPDATABLE_TABLE on insert into a view.
sql/sql_view.cc:
  Fixed bug#5505: Wrong error message on INSERT into a view
  Issue the ER_NON_INSERTABLE_TABLE error instead of the
  ER_NON_UPDATABLE_TABLE on insert into a view.
mysql-test/r/view.result:
  Added the test case for bug#5505: Wrong error message on INSERT into a view
  Corrected a few test cases after fixing bug#5505
mysql-test/t/view.test:
  Added the test case for bug#5505: Wrong error message on INSERT into a view
  Corrected a few test cases after fixing bug#5505
sql/share/errmsg.txt:
  Fixed bug#5505: Wrong error message on INSERT into a view
  Added the ER_NON_INSERTABLE_TABLE error definition.