GUI and code tweaks and fixes (#852)

* Improve format menu header descriptions
* Ensure that item status is parsed after item class from XML
* Fix column alignment in ToC.txt file
* Rename test variable and fix outdated docstring
* Fix ToC.txt underline
* Rename the Layout label on the item details panel
* Add option to emphasise H1 and H2 labels in the project tree
* Rename the main column of the novel tree to match project tree
* Use the same document icons in the outline as the project tree
* Move project tree settings to Project section of config file

nw/error.py

@@ -178,7 +178,7 @@ def exceptionHandler(exType, exValue, exTrace):
         errMsg.exec_()
 
         try:
-            # Try a controlled shudown
+            # Try a controlled shutdown
             nwGUI.closeProject(isYes=True)
             nwGUI.closeMain()
             logger.info("Emergency shutdown successful")