Added list-update error-checking dialog.

- new window pops up if errors are detected during list-update
- "More Info" buttons to include link to peerblock.com for errors
- also added 426 error-checking, for if user's PeerBlock is woefully out-of-date


git-svn-id: https://peerblock.googlecode.com/svn/trunk@678 d3e0e2f6-51e0-11de-b413-c5e99dc0a8e2