Clean up interface to PM and VFS

- introduce new call numbers, names, and field aliases;
- initialize request messages to zero for all ABI calls;
- format callnr.h in the same way as com.h;
- redo call tables in both servers;
- remove param.h namespace pollution in the servers;
- make brk(2) go to VM directly, rather than through PM;
- remove obsolete BRK, UTIME, and WAIT calls;
- clean up path copying routine in VFS;
- move remaining system calls from libminlib to libc;
- correct some errno-related mistakes in libc routines.

Change-Id: I2d8ec5d061cd7e0b30c51ffd77aa72ebf84e2565

test/test5.c

@@ -208,7 +208,7 @@ void test5d()
 
 void test5e()
 {
-/* When a signal knocks a processes out of WAIT or PAUSE, it is supposed to
+/* When a signal knocks a processes out of WAITPID or PAUSE, it is supposed to
  * get EINTR as error status.  Check that.
  */
   int n;