v4 spec updates
allow fn arrays for specific properties, re-add fn base value, allow filter_comparison as filter_value option
remove function from value array in -translate properties, modify test to allow array in value for function_stop purposes
Merge pull request #86 from mapbox/v4_spec_fixes

V4 spec fixes
Merge branch 'master' into mb-pages
Fill out more missing documentation.
Merge branch 'master' into mb-pages

Conflicts:
	docs/_generate/index.html
	docs/index.html