BREAKING CHANGE: component functions now take a global context object as
first argument (like w/ @thi.ng/hdom)

- update serialize() to accept & pass optional context
- add support for component objects
- add/update tests

- use string concat (~2.5x faster)
- skip null values

BREAKING CHANGE: rename svgdoc => svg

BREAKING CHANGE: technically identical to previous version, however
due to breaking changes and new context support in @thi.ng/hiccup,
SVG functions MUST be invoked directly now and do not support lazy
evaluation anymore. see notice in readme.

* feature/hiccup-context:
  docs(hiccup): update readme
  refactor(examples): update svg examples
  docs(hiccup-svg): resolve #19, update readme, add invocation notes
  feat(pointfree): add execjs for host calls, update readme
  refactor(hiccup-svg): rename svgdoc => svg
  docs(hiccup): update readme
  perf(hiccup): update css()
  refactor(hiccup): fix #19, add support for context object

 - @thi.ng/api@4.0.1
 - @thi.ng/associative@0.5.4
 - @thi.ng/atom@1.3.11
 - @thi.ng/bench@0.1.1
 - @thi.ng/bitstream@0.4.11
 - @thi.ng/cache@0.2.9
 - @thi.ng/checks@1.5.3
 - @thi.ng/compare@0.1.1
 - @thi.ng/csp@0.3.39
 - @thi.ng/dcons@1.0.1
 - @thi.ng/defmulti@0.3.2
 - @thi.ng/dgraph@0.2.4
 - @thi.ng/diff@1.0.15
 - @thi.ng/dot@0.1.4
 - @thi.ng/equiv@0.1.1
 - @thi.ng/errors@0.1.2
 - @thi.ng/hdom-components@2.1.4
 - @thi.ng/hdom@3.0.19
 - @thi.ng/heaps@0.2.10
 - @thi.ng/hiccup-css@0.1.21
 - @thi.ng/hiccup-svg@1.0.0
 - @thi.ng/hiccup@2.0.0
 - @thi.ng/interceptors@1.7.4
 - @thi.ng/iterators@4.1.14
 - @thi.ng/paths@1.3.7
 - @thi.ng/pointfree-lang@0.2.11
 - @thi.ng/pointfree@0.8.0
 - @thi.ng/resolve-map@2.0.3
 - @thi.ng/rle-pack@0.2.20
 - @thi.ng/router@0.1.14
 - @thi.ng/rstream-csp@0.1.70
 - @thi.ng/rstream-dot@0.2.9
 - @thi.ng/rstream-gestures@0.3.6
 - @thi.ng/rstream-graph@1.0.13
 - @thi.ng/rstream-log@1.0.21
 - @thi.ng/rstream-query@0.3.8
 - @thi.ng/rstream@1.6.11
 - @thi.ng/transducers@1.9.4
 - @thi.ng/unionstruct@0.1.10