ISIS-872: Minor tidy up of pom descriptions.
ISIS-872: trivial formatting changes to simpleapp classes.
ISIS-643: speculative fix to add a guard to an NPE if post delete processing.

... based, unfortunately, only on the supplied stacktrace and a bit of guesswork, since no reproducible case available.
ISIS-887: Removing references to isis modules from simpleapp and todoapp.

In addition:
- removed auth*_file config files
* removed ToDoItem's schedule* actions
* removed Quartz scheduler config from todoapp

also:
* removed empty ComponentFactoryRegistrarForToDoApp
* removed empty PageClassListForToDoApp
ISIS-872: removing references to components previously mothballed (in installer-registry.properties, and SystemConstants).
ISIS-884: to avoid possibility of XSS attachs, removing use of setEscapeModelStrings(false) anywhere that the content is dynamic (error messages etc).

Also, for JGrowl based messages, also explicitly calling Wicket's Strings.escapeHtml (the same underlying method that the default escaping does).
ISIS-883, ISIS-885, ISIS-846: prevent user circumventing security by hacking a URL.

for (bookmarked actions), check business rules on execution, throw new ObjectMember.AuthorizationException if fails visibility or usability checks
for entities, if paste in URL, check user has permissions to at least one property or collection, throw AuthorizationException otherwise
for entities, if cannot load object, throw AuthorizationException (avoid disclosing whether the object exists or not)
for error page, if receive AuthorizationException then suppress the stack trace to avoid leaking information to possible attacker

in addition:
- for example todoapp, simplified