updated managed bean to use the same CredStore for all the endpoint
beans. Changed the name of DB store to CredStoreDB. And Added new
Endpoint classes for Twitter and Dropbox.
review comments .. removed overriden methods.
Merge branch 'master' into ManagedBeanChanges
show invalid credentials message
Merge pull request #352 from VimalDhupar/managedBeanChanges

updated managed bean to use the same CredStore for all the endpoint
Merge pull request #356 from swatisingh10/BasicAuthFix

show invalid credentials message
Playground fixes & enhancements
Merge pull request #359 from priand/playground

Playground fixes & enhancements
Fixed the playground for Twitter and Dropbox
Merge pull request #360 from priand/playground

Fixed the playground for Twitter and Dropbox
handling NPE in Profiles and communities
correcting the error message
Merge pull request #361 from swatisingh10/FixForCommunityAndProfilesSamples

handling NPE in Profiles and communities
Preliminary support for OS gadgets
Merge pull request #362 from priand/playground

Preliminary support for OS gadgets
Upload a binary version of the playground
Merge pull request #363 from priand/playground

Upload a binary version of the playground
Merge remote-tracking branch 'root/master' into maintenance