adds a sample file with 2 columns
deletes empty line from sample data
adds sample 2 columns data to seeds
adds some more output for debugging the worker
Merge branch 'master' of github.com:fate83/SiliconHeartAnalysis

Conflicts:
	app/models/node.rb
Preparation for node help page
deleted pseudo comment
Adds validation to document file upload
Adds description to documents
shows description in overview