More robust mechanism to flush out all markers
Do cache flush only on successful flush

This change just makes the try except more concise
group common google params in a dict
Dont set XBMC property until file manipulation is complete
Set expiry of layer files based on capability contents
Some internal cleanup, and add jsonretrieve()
Settings moved to its own file.

Also added urlcache functionality to the fetching of properties
not just maps.
Remove unused 'Debug' setting
Instantiate cache once and use xbmc busy once
Remove unused functions
Clean up
Make a decorator with xbmc busy dialog