refactor view-engine to view-activity/
refactor to view/composer
refactor view-* to view-core/
move view-activity/ --> view-core/activity/
tidy
fix bootstrap failure due to site/api not being included
refactor to view-core/ui
move view-core/activity/ back to view-activity/
fix: don't require lodash in app
rename view-core/ to view-handler/