Rename "[Mm]ethod(s)" to "[Ff]unction(s)"

Only methods as programming functions are affected. Besides renaming
some actions like "Switch Between Function Declaration/Definition" this
mostly touches (api) code comments.

This is a follow-up patch to commit 872bfb7.

Change-Id: Icb65e8d73b59a022f8885b14df497169543a3b92
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/coreplugin/variablechooser.cpp

@@ -58,7 +58,7 @@ using namespace Core;
  *
  * The variable chooser monitors focus changes of all children of its parent widget.
  * When a text control gets focus, the variable chooser checks if it has variable support set,
- * either through the addVariableSupport() method or by manually setting the
+ * either through the addVariableSupport() function or by manually setting the
  * custom kVariableSupportProperty on the control. If the control supports variables,
  * a tool button which opens the variable chooser is shown in it while it has focus.
  *