Phase 1: Introduced sp_name class, for qualified name support.


sql/item_func.cc:
  Introduced sp_name class; moved some methods from item_func.h.
sql/item_func.h:
  Introduced sp_name class; moved some methods to item_func.cc.
sql/sp.cc:
  Introduced sp_name class, for qualified name support.
sql/sp.h:
  Introduced sp_name class, for qualified name support.
sql/sp_cache.cc:
  Introduced sp_name class, for qualified name support.
sql/sp_cache.h:
  Introduced sp_name class, for qualified name support.
sql/sp_head.cc:
  Introduced sp_name class, for qualified name support.
sql/sp_head.h:
  Introduced sp_name class, for qualified name support.
sql/sql_lex.h:
  Introduced sp_name class, for qualified name support.
sql/sql_parse.cc:
  Introduced sp_name class, for qualified name support.
sql/sql_yacc.yy:
  Introduced sp_name class, for qualified name support.