[Frontend] Form element style and markup fixes

WTD-610
Fixed markup in select.html;
Rebuilt associated CSS in _selects.scss;
Still to-do: checkbox valign and spacing

Conflicts:
	platform/commonUI/general/res/css/forms.css
	platform/commonUI/general/res/css/items.css
	platform/commonUI/general/res/css/theme-espresso.css
	platform/commonUI/general/res/css/tree.css

platform/commonUI/general/res/sass/_mixins.scss

@@ -74,6 +74,7 @@
 	@include box-sizing(border-box);
 //	@include box-shadow(rgba(black, 0.3) 0 1px 2px);
 	@include boxShdwSubtle();
+	border: none;
 	border-top: 1px solid lighten($bg, 20%);
 	color: $fg;
 	display: inline-block;