Added scrypt_tests from 1.6
Merge pull request #486 from patricklodder/1.7-dev-scrypt-test

Added scrypt_tests from 1.6
Shiny, retina ready OS X icon file
Fix doubled alerts in alert tests causing them to fail
Merge pull request #487 from langerhans/1.7-dev-alerttest

Fix doubled alerts in alert tests causing them to fail
fixed subsidy limit test
fix documentation of block reward schedule

there was an off-by-one error in the documentation
Merge pull request #490 from leofidus/1.7-subsidy-limit-test

fixed subsidy limit unittest