kernel: deep refactoring and cleanup

This large commit address several issues
- removed 386 directory: Jehanne is 64bit only
- simplified kernel options management
- rewritten boot process
- ported memory related stuff from 9front's 9/pc64
- removed devacpi
- removed old code
- deep refactor of awake syscall
- removed MCACHE support for mount
- fix libc's setjmp/longjmp

sys/include/memdraw.h

@@ -159,7 +159,7 @@ extern void	memarc(Memimage*, Point, int, int, int, Memimage*, Point, int, int,
 extern Rectangle	memlinebbox(Point, Point, int, int, int);
 extern int	memlineendsize(int);
 extern void	_memmkcmap(void);
-extern void	memimageinit(void);
+extern int	memimageinit(void);
 
 /*
  * Subfont management