Rework the logic that generates a schema for tables created using

Rework the logic that generates a schema for tables created using
"CREATE TABLE ... AS SELECT ...".  Instead of trying to copy the raw
datatype string from the right-hand side, just make the type one
of TEXT, INT, REAL, NUM, or nothing.  This is much simpler than
trying to parse and quote datatype strings.  Other minor
implifications to build.c are bundled with this change. (CVS 6626)

FossilOrigin-Name: 33cf83591e6e13875ef6ada5b8ac8ab07619d8bc