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/documentmanager.h

@@ -84,7 +84,7 @@ public:
     static void setCurrentFile(const QString &filePath);
     static QString currentFile();
 
-    // helper methods
+    // helper functions
     static QString fixFileName(const QString &fileName, FixMode fixmode);
 
     static bool saveDocument(IDocument *document, const QString &fileName = QString(), bool *isReadOnly = 0);