Specified selector to div.(col)?border instead of just .(col)?border within src/grid.css.  Resolves Lighthouse Issue #47 (http://blueprintcss.lighthouseapp.com/projects/15318/tickets/47-srcgridcss-uses-colborder-selector-screencss-uses-divcolborder)
Specified selector to div.(col)?border instead of just .(col)?border within src/grid.css.  Resolves Lighthouse Issue #47 (http://blueprintcss.lighthouseapp.com/projects/15318/tickets/47-srcgridcss-uses-colborder-selector-screencss-uses-divcolborder)

beppec56/blueprint-css,shinphoowin/blueprint-css,chriseppstein/blueprint-css,cutefrank/blueprint-css,tladesignz/blueprint-css,joshuaclayton/blueprint-css,sagax/_blueprint-css,beppec56/blueprint-css,shinphoowin/blueprint-css,sagax/_blueprint-css,blueprintcss/blueprint,cutefrank/blueprint-css,baiyanghese/blueprint-css,cofffeee/test