bugfixes for psychology and continued refactoring
Merge branch 'master' into psychology-refactor-bugfixes
merge of new economics with updated master and psychology bugfix branch
intial build of CSS files for eventual diff with bugfixes
fix for chapter text and number subheader for References section.
numbering reset for exercises for physics text utilizing a physics specific slot
Merge pull request #470 from Connexions/physics-numbering-fix

Numbering reset for exercises in Physics text
addition of quotes for economics features and fix for preface mixin parameters
move chapter-objectives title into slots
Merge branch 'phil-econ-objectives-title' into psychology-refactor-bugfixes
Merge pull request #464 from Connexions/psychology-refactor-bugfixes

References chapter subheader fix for psychology and across texts
Merged master into refactor-economics-wip.