Fix: TypeError: Cannot read property "exists" from undefined.

[xavierhd]

Added exists to the property saved right from the start.
When deleting after the refresh, property which are TRUE are reseted to null, else they will alway be true forever since they would be saved as TRUE.

Removed the print "Refreshing " + name.
Reason: Having to click OK for each datatable config does not help to control the plugin, it slow down the process. Here is a use case:

• User has 10 datatable to refresh.
• He start the process.
• The user need to click ok for each config (he cannot click cancel).

Without the print, the whole refresh is made automatically without intervention. (Start and forget)

[sajacy]

Thanks for your contribution. Will release a new version asap

[xavierhd]

No problem!