Reorganize a lot of code (once again)
Fix compatibility with Windows

* Fix jar file name retrieval in Main.
* Fix problems with backslashes.
* Add proper priority levels for loading order to OS.SET_RUNNING.
* Replace the jdk-only "jps" program with platform-specific program
calls (TempFileManager).
(Mostly) move ProcState to shared and rename it to WorldProcessState

That is required because a new WorldProcessPlaceholder class will be
introduced soon.
Add default removal of registered client program event handlers

Event handlers registered using the
ClientProgramWindowSkeleton.registerEventHandler() are now automatically
removed once the program window is closed.
Shorten ProgStateUtils interruption stopper registering executor calls
Remove Process.APPLY_STATE method

Instead, the more meaningful methods "SUSPEND", "RESUME", "INTERRUPT"
and "STOP" should be used. Also rename "IS_STATE_APPLIED" to
"IS_STATE_APPLIED_RECURSIVELY" and add a logger for easier issue
tracking.
Use overhauled naming scheme for events

* Program-specific events for world processes must now follow the scheme
"PROG_WP_EventName" (e.g. "FMP_WP_ChangeDirCommand").
* Program-specific events for world process users (e.g. clients) must
now follow the scheme "PROG_SBPWPU_EventName" (e.g.
"FMP_SBPWPU_UpdateViewCommand").
* Note that both rules also apply to generic program events.
Add command for interrupting world process users

For example, it could notify a graphical client process that its partner
world process has been killed from outside using the process manager. By
default, the ClientProgramWindowSkeleton adds a handler for closing the
window (and therefore terminating the client program) when such an event
arrives at the process.
Use ConcurrentLinkedQueues for RunnableInvocationProviders
Fix wrong thread being used for debug computer startup in Main
Add client-side event handler exception handler
Overhaul the customized TWL TreeModel
Add finger mouse cursor to tree table +/- buttons
Clean up the file manager program l10n files
Fix TickSchedulerUpdater

Before this commit, the TickSchedulerUpdater tick action didn't do
anything because of some issues. This fix uses Classmod's new TreeWalker
to implement the scheduler collecting part.
Add automatic name trimming to File.NAME
Rewrite Process.GET_SESSION_PROCESS to first look at the current process
Migrate client process interruption process state listener into function
Introduce (theoretical) client program config splitting
Add WorldProcessPlaceholder