Splitted and improved PDF generation for invoicing documents
Fixed incorrect date handling for non invoice-based documents
Correctly handles greyscale and custom colored reports
Properly handle page headers and footers
Support common used paper sizes
Updated translations
Fixed page_sizes __all__ definition
Merge branch 'feature/pdf_split' into develop
Merge branch 'develop' of github.com:Naeka/vosae-app into develop

Conflicts:
	www/account/locale/en/LC_MESSAGES/django.po
	www/account/locale/en_GB/LC_MESSAGES/django.po
	www/account/locale/fr/LC_MESSAGES/django.po
	www/data_liberation/locale/en/LC_MESSAGES/django.po
	www/data_liberation/locale/en_GB/LC_MESSAGES/django.po
	www/data_liberation/locale/fr/LC_MESSAGES/django.po
	www/organizer/locale/en/LC_MESSAGES/django.po
	www/organizer/locale/en_GB/LC_MESSAGES/django.po
	www/organizer/locale/fr/LC_MESSAGES/django.po