added picasa data defaultlocation

hello sisoo,

I was looking for a tool to get People info from picasa and found your solution. It works without problems for me.

From the csv that your program creates i can easily generate exiftool commands to embed people into the image sidecar *.xmp files.

I added the windows defaultlocation of picasa data dir %LOCALAPPDATA%/Google/Picasa2/db3 so user does not has to set it every time.