used wikia.fluidlayout module to get all the sizes
added gerRightRailWidth to wikia.fluidlayout module
refactored PageControls.js so it uses wikia.fluidlayout module and passes isWidePage to wikia.preview module
added a getter method which returns a different previewTypes object depending on the fact if "page is wide"
small refactoring and adjustments
jsling: removed redudant initialPreviewWidth variable
jsling: removed unused variables
jslint: added semicolon; less "var" in scalePreview() method
extracted adding edit summary to seperate method and fix it for fluid layout
added new mixin in responsive-mainpage-tag.scss so the rules for media-query can be reused in edit preview; fixed edit preview for mainpages
small refactoring and explanation added
fixed regression making article preview modal smaller after adding edit summary
DAR-2506 fixed previewing main pages of different widths
DAR-2506 change in the logic of previewing main pages
DAR-2366, small cleanup refactoring
DAR-2534 reverting DAR-2182 fix
DAR-2366, add missing 10 px margin to rail width
DAR-2366, fix main page preview modal size
Manually merged branch 'dev' into DAR-2382
Manually merged branch 'dev' into DAR-2366