1. add a config to decide whether refresh to page one or stay the latest pagenum when switching happens.
2. set a default height value to Dom  `.woo-pcont` when switching happens. If u don't do this, the scrollbar position will move to top due to the height collapse;
add try ... catch(e) to deal with JSONparse process
Add a config `refreshwhenswitch`
Merge pull request #11 from balibell/master

Add a config `refreshwhenswitch` and set a default height value to node .woo-pcont