Merge pull request #2 from thuutin/master

adapt to pdfminer API changes

reactivated errors

removed logs

now Creating units only for visible layers

using a separate file to test

typo

now create the units

added files to the ignore list

started to extract some data

added pp and benchmarking

starting to parse pads

init psd.rb

added explanation for jpg/png file extraction

no more choice between png or jpeg