Allow tailoring of ICU locales with custom rules

Update types in smgr API

Add const to BufFileWrite

Update types in File API

Remove unnecessary casts

Change argument type of pq_sendbytes from char * to void *

Use appendStringInfoString instead of appendBinaryStringInfo where possible

Change argument of appendBinaryStringInfo from char * to void *

Allow underscores in integer and numeric constants.

Remove AggregateRelationId from recordExtObjInitPriv()

Refactor recordExtObjInitPriv()

Add BufFileRead variants with short read and EOF detection

Fix some BufFileRead() error reporting

New header varatt.h split off from postgres.h

Code cleanup

Common function for percent placeholder replacement

pg_upgrade: Make testing different transfer modes easier

pg_upgrade: Add --copy option

Fix come incorrect elog() messages in aclchk.c

Static assertions cleanup

Rearrange some static assertions for consistency

Refactor ExecGrant_*() functions