5.2.0 release

* Fix typo in `boot.core` dependency

* The `#'tailrecursion.hoplon/on!` function is now a multimethod whose
  default dispatch is to add jQuery event handlers. Extending this
  multimethod allows the addition of other event handlers e.g. HammerJS
  etc.

  Example:

  (defmethod on! :dragleft
    [elem key callback]
    (.. (js/Hammer elem) (on "dragleft" callback)))

* Elements can now be wired to Javelin cells without the `do-` or `on-`
  attribute key prefixes. The `#'tailrecursion.hoplon/add-attributes!`
  function now dispatches on the type of the attribute value, i.e. if
  the value is a cell then the element is wired to the `do!` multimethod
  and if it's a function then the element is wired to the `on!` multi-
  method.

  Example:

  (div
    :do-toggle (cell= (< 100 amount))
    :on-click #(swap! clicks inc)
    "This is a div!")

  can now be written as

  (div
    :toggle (cell= (< 100 amount))
    :click #(swap! clicks inc)
    "This is a div!")

* The `do-` and `on-` attribute key prefixes still work as before, so
  this is not a breaking change.

* The `tailrecursion.hoplon.svg` namespace was added, containing HLisp
  SVG elements.

* Add live-reload functions in the `tailrecursion.hoplon.reload`
  namespace to facilitate automatic reloading of the page and CSS
  resources during development for "live coding".