Add a Introduction Certificate Extension
Merge branch 'refactoring' into web-of-trust
Add Test case for Web-of-Trust, add get/set methods in certificate-extension classes
Fixed encoding bugs of DER Integer class
Merge branch 'refactoring' into web-of-trust
Introduction certificate extension is working now
Move verification steps from Keychain to PolicyManager, move CacheCertificate from Keychain to PolicyManager
Merge branch 'refactoring' into web-of-trust
Add basic web of trust policy manager
Remove PolicyManager related methods from Keychain, add getPolicyManager method instead
Merge branch 'refactoring' into web-of-trust
Remove CertificateType in Certificate, the type of certificate should be told from certificate name
Change private members to protected members for future extension
Merge branch 'refactoring' into web-of-trust
Add IntroCertificate Class
Adjust PolicyManager Interface, remove unnecessary methods, make it more abstract
Merge branch 'refactoring' into web-of-trust
Add implementation of IntroductionCertificate
Add BasicWOTPolicyManager
1. Slightly change the signingByIdentity methods of keychain.
2. Add comments into PolicyManager interfaces
Add SimplePolicyManager and NoVerifyPolicyManager