DDF-731  fixed typos in addition of guava lib to pom
DDF-731  fixed typos in addition of guava lib to pom
DDF-733  moved CommonCallback, PropertiesLoader, and STSClientConfiguration to security-core-api in platform app in support of usage by spatial app
DDF-733  moved PropertiesLoader to different package to avoid split-package issues
DDF-733  removed CommonCallbackHandler throughout all security code; fixed path determination to security properties file