BugFix: Custom hardware properties on Windows

Re-writing default AVD config files result in missing backslashes
Resulting in error's such as: 
 - emulator: ERROR: This AVD's configuration is missing a kernel file!!

Properties.load will remove single backslashes. But doubling them beforehand is a dirty workaround ... for now.
http://stackoverflow.com/questions/5784895/java-properties-backslash