Play movie: missing indication of checksum mismatch about bizhawk HOT 2 CLOSED

r2187 adds a SHA-1 checksum to movie headers, presents it in the "Play movie" 
properties and highlights in red if there is a mismatch. This can be improved 
by providing the current ROM checksum like FCEUX, Snes9x-rr and vba-rr so they 
can be compared by the user.

Movie checksum verification still does not work for imported movies. This is to 
be expected, as SHA-1 checksums may not be present in the pre-imported movie 
header (e.g. .fm2 has MD5 only).

Added a feature where a rom mismatch will enable a tooltip in the header list 
showing the current sha1. This in addition to accurate reporting of various 
mismatches (such as sha1 and system id) sufficiently closes this issue.

Let me know if there is any other issues with this (and if googlecode doesn't 
allow commenting on closed issues, let me know that too!)