Bump versions
Add checksum checking support

In passing, alter Postgres version of various stamps (we're currently targeting
version 9.3), and refactor some items.
Fix enum definitions to conform to Postgres style
Minor tweak
Either report HEAP_XMAX_SHR_LOCK or HEAP_KEYS_UPDATED
Add -o block option to exclude page items

This is a useful way of lowering the verbosity of pg_filedump output.