Pin libsass to 0.5.1 to avoid compilation errors when setting up new build
Add main_image, heading and quote fields to standard page
Fix image chooser on standard page
Migrations and template changes for new fields on standard page
Add span button to hallo js
Add a break between intro and body on standard page
Add email and Clients to standard page model, update template
Merge branch 'develop'

Conflicts:
	torchbox/templates/torchbox/standard_page.html