Dependency updates

Upgrade to spring framework 5.1.x and spring-security 5.1.x as well as a bunch of other 3rd party dependencies.

• Fixes #4 Spring framework and spring security framework upgrade
• Fixes #6 Copyright year change
• Fixes #7 Third-party dependencies update
• Fixes #8 Gradle build file dependency update
• Fixes #9 Buildr build file dependency update
• Fixes #11 Maven plugin version update

Changes to work with latest version of spring and spring-security

Enhancements

• Support for spring framework 4.1.5.RELEASE
• Support for spring security 3.2.6.RELEASE

Bugs

• #2 Remove deprecated PasswordEncoder
• #3 Issue with media subfolder urls in Windows