demo driver page and skeleton js library

[SafeSlingerProject]

• should accept 2 fields: server and secret
• server should default to https://slinger-dev.appspot.com
• 2 fields should pass to javascript library
• library should validate 2 fields for format: server = url style, secret = not empty

[SafeSlingerProject]

Also, physical endpoints to the library:

• UIs for requesting input: number users, lowest group number, 3-word phrase.
• http POST calls to assignUser, syncCommits, syncData, syncSigs, syncNodes, syncMatch

UI: server=string, secret=string
library: server=string, secret=binary/byte-array

[mwfarb]

@shrimalmadhur The skeleton was done some time ago in your first commit, so I'm closing this one. I've added a number of issues which breaks the whole project down into smaller parts so we can track progress using milestones.

I've created a mile stone for 2-party exchange to track phase 1 and one for multiparty tasks to track the follow up phase.