Adding fixes for empty async value

Merge pull request #16 from gastonrobledo/master

Update from fork.

Release 1.1.9

Merge pull request #15 from gastonrobledo/master

propagate error on each helper

Release 1.1.8

Merge pull request #14 from gastonrobledo/master

increase version of handlerbar and update with latest 4.3.0 changes

Release 1.1.7

Adding changes to use @first, @last, @index, @key on a stream iteration

1.1.6

Merge pull request #12 from gastonrobledo/master

bump version, fix vulnerabilities and update readme

1.1.5: Merge pull request #11 from gastonrobledo/master

• Adding changes to support partials properly when using multiple instances of library
• Adding some fixes to async helpers