Add coalesce streams test
Renamed build notebook funct so nose test doesn't run it
Added base transformers test class and added CSSHTMLHeaderTransformer tests
Inlining is not an attribute of resources
Updated comment
Removed invalid comment (from previous commit) and added a new line
Added png output
Enabled Transformer
Added extract output test
Added latex transformer test
Added utility function to build a proper resources dict
Added revealhelp transformer tests
Added sphinx transformer tests
Add svg2pdf transformer tests
Fixes small things pointed out by @minrk
py3 unicode fix for output_png key
Attempt 2, fix py3 png encoding
Extracted output are now test against byte arrays instead of strings
Expanded transformer pass line, for easier debugging
Removed extra line added accidently in last commit