Fixes to rCharts_hv

I have made some minor fixes to resolve all the problems you raised. Especially:

1. Populating select controls on page load.
2. Positioning of chart.

The changes I made are self-explanatory, but if you have questions do continue the discussion here. My code is a little crude too, but I don't want to prematurely optimize. Once we have it working, we can go through a round of refactoring and clean up the code.

Terrific work on the plugin btw!