Use cstring_to_text_with_len when length is known.

This avoids a potentially-expensive extra call to strlen().

David Rowley
Replace appendPQExpBuffer(..., <constant>) with appendPQExpBufferStr

Arguably makes the code a bit more readable, and might give a small
performance gain.

David Rowley
Spell SQL keywords in uppercase in pg_dump's query.

The server won't care, but let's be consistent.

David Rowley.