"Help" box link, URI-T fixes

[a-mabe]

• Added "Help" link to explain differences between URI-R, URI-M, and URI-T
• Fixed some URI-T input issues
• Added message to display when only latest 5000 mementos are analyzed
• Changed simhash log in progress box to hex instead of binary

[ibnesayeed]

Did you test it? Is it ready to be merged?

[a-mabe]

Yes, it is tested and working. Thanks!