[DGD] Kernel Library: Optional tracking of predefined resources

[Shentino]

After much delay, I have made an update to the kernel library.

Tracking of predefined resources such as stack, ticks, objects, and file
quota is now optional, and such resources can be added or removed manually
as with user defined resources.

Formerly predefined resources now simply serve as the default starting set
of resources.

The only criteria regarding reactivation of a predefined resource is that
all of them except for tick usage may not be decayed.
Bit rot is forbidden here.

Some minor corner case handling of attempted access to resources that do not
exist has also been added.

An absent resource is considered to have a count of zero and an unlimited
quota for all users, and attempts to manipulate quantities for such
resources will short circuit and succeed with no effect.  Attempting to
change a limit for such a resource however, formerly provoking an array
bounds violation, now throws a "No such resource" error.

Please note that predefined resources, if temporarily deleted, are not
retroactively corrected.  It is the responsibility of the end user to audit
and/or reconcile any resource counts as needed.

Hopefully by making resource tracking optional in many cases, the kernel
library will remain useful in the foreseeable future for Hydra, and should
in any case improve performance in environments where some resources do not
need to be tracked.

Comments or bug reports appreciated.