Define ROW and STATEMENT as parser tokens.

Define ROW and STATEMENT as parser tokens.
Use explicit tokens to decode CREATE TRIGGER clauses.
Allow ROW and STATEMENT as column identifiers.
Fix CAST syntax to require parens per SQL92 spec.
Define TypeId to allow correct translation of type names in CREATE FUNCTION
 and other statements. Need to do this without looking up defined type
 names because CREATE FUNCTION can specify undefined (new) types.
Define UserId to complete removal of "Id" generic entity.
Define xlateSqlFunc() to convert SQL92 CHARACTER_LENGTH() and CHAR_LENGTH()
 functions to calls to length().
Define func_name parser entity for contexts requiring a function name.
Have xlateSqlType() translate "float" to "float8".