Fixes for RStudio internal browser preview

RStudio uses slightly old rendering engine based on WebKit, so it needs some improvements to be done in the JavaScript code to overcome its limitations.

This PR provides the following fixes:

1. Lo-Dash compatibility build is used (it works with both «new» and «old» environments)
2. `Date.parse()` «polyfill» for working with ISO 8601 dates (introduced in EcmaScript 5.1)

With these fixes applied I successfully run `ohlc-trades.R` example in my RStudio:

![rstudio-canvas-annotations](https://cloud.githubusercontent.com/assets/290451/3270138/021d8072-f2fc-11e3-9ded-4c5b72503dc2.png)

So, this PR fixes the following issues:

* https://github.com/danielkrizian/rChartsDygraphs/issues/10
* https://github.com/danielkrizian/dygraphs/issues/15