Fix #56 - decrease default keep-alive interval window for Heroku

As per Heroku http-routing docs[1]:
"After a dyno connection has been established, HTTP requests have an initial 30 second window in which the web process must return response data (either the completed response or some amount of response data to indicate that the process is active). Processes that do not send response data within the initial 30-second window will see an H12 error in their logs."

So to play better with Heroku timeouts, have decreaeed the default
Sente keep-alive intervals as follows:
`:ws-kalive-ms` - 38000 -> 25000
`:lp-kalive-ms` - 38000 -> 25000

https://devcenter.heroku.com/articles/http-routing#timeouts
Add rationale for long-polling over chunked encoding
Misc hk
Reference example: add link to Light Table Cljx config Groups post
v0.15.1
Reference example: add some extra comments on auth procedure
README housekeeping
Docstring housekeeping
Further `chsk-url-fn` doc tweaks
Bump example project's `ring-anti-forgery` dep
compojure.handler namespace is deprecated in favor of ring-defaults
Housekeeping: 694d6f9
README: Add note re: modifying sessions
Break Versioning
Experimental support for transit (@ckarlsen84)
Bump deps (incl. :dev Clojure 1.7.0-alpha1)
NB Merged refactor [#12], [#59], [#60], [#66], [#67] (@ckarlsen), [#68], [#69] (@hugoduncan), more

Completely refactored Sente's client<->server data handling for:
  * Greater consistency, simplicity, robustness.
  * Increased efficiency (smaller cb ids, leaner cb wrapping format).
  * Pluggable serialization.

The pluggable serialization brings optional support for Transit, incl.
JSON and MessagePack over Transit (thanks to @ckarlsen for getting the ball
rolling on this!).

An early, experimental FlexiPacker is provided that allows per-payload
format selection and simple heuristic-based auto format selection for highly
efficient client<->server data comms in a wide range of use cases. This will
likely become Sente's standard (if not default) package format in future.

Other changes in this squashed commit include:
  * General code review + clean-up.
  * Improved logging.
  * A new client-side `chsk-destroy!` API fn.
  * Improved client+server router support for component-style configs
    (thanks to @hugoduncan for this!): server+client side routers now
    both receive `event-msg`s, and those `event-msg`s contain more
    useful goodies.
  * Client-side router now traps+logs errors like the server-side router.
  * Improve reference example's compatibility with LightTable.
Remove Transit :msgpack opt (seems to be unavailable)
v1.0.0-SNAPSHOT
v1.0.0