Project tree status and total word count changes (#882)

* Fix some inconsistencies in source file docstrings
* Remove the option to show status text in project tree
* Change how total word counts are calculated and propagated
* Fix tests and improve coverage
* Add setting in preferences
* Add missing word count timer to config file

tests/reference/baseConfig_novelwriter.conf

@@ -1,5 +1,5 @@
 [Main]
-timestamp = 2021-08-30 21:27:27
+timestamp = 2021-09-10 00:23:50
 theme = default
 syntax = default_light
 icons = typicons_light
@@ -26,7 +26,6 @@ fullscreen = False
 [Project]
 autosaveproject = 60
 autosavedoc = 30
-fullstatus = True
 emphlabels = True
 
 [Editor]
@@ -57,7 +56,9 @@ spellcheck = en
 showtabsnspaces = False
 showlineendings = False
 showmultispaces = True
+wordcounttimer = 5.0
 bigdoclimit = 800
+incnoteswcount = True
 showfullpath = True
 highlightquotes = True
 allowopensquote = False