rename `flatMapWithConcurrencyLimit` to `flatMapConcurLimit`
add `transform` method
add `timestamp` method
rewrite most examples using `sequentially` instead of `emitter`
add `Kefir.bus()`
use uncompressed kefir version in docs
add changelog
link to changelog from docs
update deps
0.2.8
Merge branch 'master' into gh-pages

* master:
  0.2.8
  update deps
  link to changelog from docs
  add changelog
  use uncompressed kefir version in docs
  add `Kefir.bus()`
  rewrite most examples using `sequentially` instead of `emitter`
  add `timestamp` method
  add `transform` method
  rename `flatMapWithConcurrencyLimit` to `flatMapConcurLimit`