Add single selection menu item

menus/darwin.cson

@@ -109,6 +109,7 @@
     submenu: [
       { label: 'Add Selection Above', command: 'editor:add-selection-above' }
       { label: 'Add Selection Below', command: 'editor:add-selection-below' }
+      { label: 'Single Selection', command: 'editor:consolidate-selections'}
       { label: 'Split into Lines', command: 'editor:split-selections-into-lines'}
       { type: 'separator' }
       { label: 'Select to Top', command: 'core:select-to-top' }

menus/linux.cson

@@ -108,6 +108,7 @@
       { label: 'Add Selection &Above', command: 'editor:add-selection-above' }
       { label: 'Add Selection &Below', command: 'editor:add-selection-below' }
       { label: 'S&plit into Lines', command: 'editor:split-selections-into-lines'}
+      { label: 'Single Selection', command: 'editor:consolidate-selections'}
       { type: 'separator' }
       { label: 'Select to &Top', command: 'core:select-to-top' }
       { label: 'Select to Botto&m', command: 'core:select-to-bottom' }

menus/win32.cson

@@ -127,6 +127,7 @@
       { label: 'Add Selection &Above', command: 'editor:add-selection-above' }
       { label: 'Add Selection &Below', command: 'editor:add-selection-below' }
       { label: 'S&plit into Lines', command: 'editor:split-selections-into-lines'}
+      { label: 'Single Selection', command: 'editor:consolidate-selections'}
       { type: 'separator' }
       { label: 'Select to &Top', command: 'core:select-to-top' }
       { label: 'Select to Botto&m', command: 'core:select-to-bottom' }