Disallow non-Namecoin tx with name outputs.

This is currently still allowed, but will be disallowed with the
upcoming fork.  It is something that isn't done by the official client
anyway.
Add block height to coinbases.  (BIP 30)

The block height in the coinbase prevents non-unique coinbase tx from
being generated.  No checks for BIP30 are done, though.
Disallow auxpow blocks that have an auxpow themselves.

This is a strange situation, but one that is currently allowed.  Forbid
it in the upcoming softfork.
Disable spawn area death.

With the upcoming hardfork, disable spawn area death.
Merge pull request #92 from domob1812/txversion

Fix some "strange situations" in the upcoming fork.
Merge pull request #93 from domob1812/no-spawn-death

Disable spawn area death.