Reorganize defines.inc

The sizes of the kernel's tables have been changed to reflect issue #18
on Github, namely:

- 32 active threads
- 16 active libraries
- 16 pending signals
- 16 active file streams

There is an issue somewhere in KnightOS that causes programs to crash when
they exit now; this is probably an issue with a hardcoded constant.
Fix kernel.inc

The stuff in defines.inc was hardcoded into kernel.inc; the parent
commit's changes didn't affect userland code.

This commit closes #18 on GitHub.
Cleaned up new include files
Renaming files
Merge branch 'master' into writable_fs