Linking Hadoop in intro text.
Bolding the sentence about Python files.
Added reference to an "integration" chapter (i.e., integrating with Apache, etc.).
Added skeleton source files.
Filled in "basic usage" chapter, along with small change to tangelo-passwd (script supports file format example as documented in basic usage).
Added section header to integration chapter.
Removed "advanced features" chapter, in place of extensive chapter on Python services.
Starting to discuss example Tangelo service.