Add documentation for Selection.expandOver*

src/edit-session.coffee

@@ -1275,9 +1275,7 @@ class EditSession
   joinLine: ->
     @mutateSelectedText (selection) -> selection.joinLine()
 
-  # Public:
-  #
-  # FIXME: No idea what this does.
+  # {Delegates to: Selection.expandOverLine}
   expandLastSelectionOverLine: ->
     @getLastSelection().expandOverLine()
 
@@ -1300,9 +1298,7 @@ class EditSession
   selectWord: ->
     @expandSelectionsForward (selection) => selection.selectWord()
 
-  # Public:
-  #
-  # FIXME: No idea what this does.
+  # {Delegates to: Selection.expandOverWord}
   expandLastSelectionOverWord: ->
     @getLastSelection().expandOverWord()
 

src/selection.coffee

@@ -120,9 +120,8 @@ class Selection
     @wordwise = true
     @initialScreenRange = @getScreenRange()
 
-  # Public:
-  #
-  # FIXME: I have no idea what this does.
+  # Public: Expands the newest selection to include the entire word on which
+  # the cursors rests.
   expandOverWord: ->
     @setBufferRange(@getBufferRange().union(@cursor.getCurrentWordBufferRange()))
 
@@ -137,9 +136,10 @@ class Selection
     @wordwise = false
     @initialScreenRange = @getScreenRange()
 
-  # Public:
+  # Public: Expands the newest selection to include the entire line on which
+  # the cursor currently rests.
   #
-  # FIXME: I have no idea what this does.
+  # It also includes the newline character.
   expandOverLine: ->
     range = @getBufferRange().union(@cursor.getCurrentLineBufferRange(includeNewline: true))
     @setBufferRange(range)