Fixed scrypt N-param bug and added time calc

Fixed an error in the way the N parameter was being using in SCrypt, should be using 2^N instead of just N.
Also added benchmarking to the scrypt calculation so we can start to get a handle on scrypt execution time for different tunings of the parameters
Added export master key example
Tweaking scrypt params to increase compute time

Standard on-device compute times should be around 2 seconds
Exporting master key time should be around 60 seconds
Added TLD Parsing to latest (2013.10.09) version of spec
Added TLD Parsing to latest (2013.10.09) version of spec + removed broken test URL
Accepted new tld parser from brianc1969
Moved from base64 to base64Url safe encoding

Added first JUnit tests
Updated Readme.

Updated readme, added sections for license, building sqrl, contributions, and attributions
Updated .gitignore to include gradle build output
Removed extra print from test-case
Refactored client helper functions into classes in crypto package
SCrypt benchmark method