Simplify abstract; move OT/CRDT to end.

[toomim]

I've heard some readers were not clear that:

• the 4 braid extensions can be used independently
• braid is useful even if you don't want OT or CRDT stuff

This abstract tries to simplify and clarify. It articulates the 4 extensions earlier, and more clearly, and then describes the generalized power that comes from putting them together near the end.

It also removes the prose about web frameworks and app architecture, because the term "local-first" probably suffices to imply that these days.

[toomim]

Old Abstract:

   Braid is a set of extensions that generalize HTTP from a state
   *transfer* protocol into a state *synchronization* protocol.  Braid
   puts the power of Operational Transform and CRDTs on the web,
   improving network performance and enabling natively peer-to-peer,
   collaboratively-editable, offline-first web applications.

   Braid is composed of four extensions to HTTP:

     1. VERSIONING on resources
     2. SUBSCRIPTIONS on GET requests
     3. PATCHES created from Range Requests
     4. MERGE-TYPES that specify OT or CRDT behavior

   These extensions are independent; each provides a distinct value for
   a stand-alone use-case.  However, when used together, they enable a
   web resource to synchronize automatically across multiple clients,
   servers and proxies, and support arbitrary simultaneous edits by
   multiple writers, under arbitrary network delays and partitions,
   while guaranteeing consistency using a OT, CRDT, or other algorithm.

   These synchronization features provide a step towards a standard for
   the dynamic internal state of websites.  Web programmers currently
   synchronize state across clients and servers with layers of
   non-standard Javascript frameworks.  A synchronization standard built
   upon REST can enable programmers to read and write the internal state
   of any website as easily as a local variable on their own site.  This
   could enable a separation of UI from state, and allow any user to
   edit or choose their own UI for any website's state.

New Abstract:

   Braid is a set of extensions that generalize HTTP from a state
   *transfer* protocol into a full-featured state *synchronization*
   protocol.

   Braid is composed of four independent extensions to HTTP:

     1. VERSIONING of resource history
     2. SUBSCRIPTIONS to updates over time
     3. PATCHES to ranges of space
     4. MERGE-TYPES that specify OT or CRDT behavior

   Each extension provides a distinct value for a stand-alone use-case.

   However, these extensions can compose together to support the full
   power of CRDTs and Operational Transforms directly on web resources.
   This allows multiple writers to make simultaneous mutations to
   arbitrary content-types, under arbitrary network delays and
   partitions, while guaranteeing consistency across multiple clients
   and servers.  This improves caching and network performance, and
   enables natively peer-to-peer, collaboratively-editable, local-first
   web applications.