Mother 3 fix, refined to not break Metroid Fusion or hopefully anything else

git-svn-id: https://svn.code.sf.net/p/vbam/code@1225 a31d4220-a93d-0410-bf67-fe4944624d44
Remove useless backup enabled checks in read handlers.
Fix illegal halfword and byte reads.

git-svn-id: https://svn.code.sf.net/p/vbam/code@1226 a31d4220-a93d-0410-bf67-fe4944624d44