cleaner s3 image uploading, config switch to disable (disabled by default in dev)
prod version of script
Merge pull request #780 from code-dot-org/staging

DTT
fix nil nomethod exception in gallery activities
fix undefined skin
link to gallery from homepage (static iamges)
Merge pull request #781 from code-dot-org/staging

DTT
link to gallery from homepage (static iamges)
Merge pull request #782 from code-dot-org/staging

link to gallery from homepage (static iamges)
Merge pull request #783 from code-dot-org/test

DTP