build: Add missing tests and gnulib modules suggested by autoscan. * build-aux/bootstrap_gnulib.conf: Add float and stddef header modules. * libgnu/Makefile.am: Automatically re-generated when module list changed. * configure.ac: Add function check for isascii, modf, pow, sqrt. Add function check for chown, ftruncate, mmap, munmap when building GUI. * libinterp/interpfcn/toplev.cc: Add gnulib:: qualifier to malloc call. * liboctave/util/oct-shlib.cc: Add gnulib:: qualifier to strerror call.

--- a/build-aux/bootstrap_gnulib.conf	Fri Sep 28 15:04:09 2012 -0400
+++ b/build-aux/bootstrap_gnulib.conf	Fri Sep 28 14:22:54 2012 -0700
@@ -31,6 +31,7 @@
   fcntl
   fflush
   filemode
+  float
   floor
   floorf
   fnmatch
@@ -69,6 +70,7 @@
   sigprocmask
   sleep
   stat
+  stddef
   stdint
   stdio
   strerror