Spring Security Auto Configuration

[dogeared]

The Spring Security integration should be enabled (or not) based both on classpath AND properties.

Scenarios:

1. Spring Security is in classpath: We enable Stormpath Spring Security integration
2. Spring Security is not in classpath: we disable Stormpath Spring Security integration
3. Spring Security is in classpath and Stormpath Spring Security is disabled in properties file: we disable Stormpath Spring Security integration