Test comparison CSV file was missing last row
Hyperlink fix: id attribute is actually r:id - rspec was failing
Excel to_csv for Link cell should be url not string
Adding check for id presence - what rui-castro had done in the first
place

Conflicts:
	lib/roo/excelx.rb
refactor out cell handling to separate method

Conflicts:
	lib/roo/excelx.rb
refactoring zipfile processing - removing redundant zip open

Conflicts:
	lib/roo/excelx.rb
Speedup xlsx file parsing. Closes #55, #135