Support selecting editor lines from the gutter

Mouse events that occur in the gutter are forwarded to the
rendered lines with the y-coordinate translated to be the
leftmost pixel of the editor to simulate the event originating
from column 0 of the current line row.

Closes #287

src/app/editor.coffee

@@ -385,7 +385,7 @@ class Editor extends View
       @destroyFold($(e.currentTarget).attr('fold-id'))
       false
 
-    @renderedLines.on 'mousedown', (e) =>
+    onMouseDown = (e) =>
       clickCount = e.originalEvent.detail
 
       screenPosition = @screenPositionFromMouseEvent(e)
@@ -403,6 +403,8 @@ class Editor extends View
 
       @selectOnMousemoveUntilMouseup()
 
+    @renderedLines.on 'mousedown', onMouseDown
+
     @on "textInput", (e) =>
       @insertText(e.originalEvent.data)
       false
@@ -419,6 +421,10 @@ class Editor extends View
       @gutter.widthChanged = (newWidth) =>
         @scrollView.css('left', newWidth + 'px')
 
+      @gutter.on 'mousedown', (e) =>
+        e.pageX = @renderedLines.offset().left
+        onMouseDown(e)
+
       @subscribe syntax, 'grammars-loaded', =>
         @reloadGrammar()
         for session in @editSessions

src/app/gutter.coffee

@@ -23,13 +23,6 @@ class Gutter extends View
     highlightLines = => @highlightLines()
     editor.on 'cursor:moved', highlightLines
     editor.on 'selection:changed', highlightLines
-    @on 'click', '.line-number', (e) =>
-      row = parseInt($(e.target).text()) - 1
-      position = new Point(row, 0)
-      if e.shiftKey
-        @editor().selectToScreenPosition(position)
-      else
-        @editor().setCursorScreenPosition(position)
 
     @calculateWidth()