gnu: cmake: Bump to 2.8.12

* gnu/packages/cmake.scm: bump to 2.8.12

gnu: subversion, cmake: Clean up descriptions.

* gnu/packages/cmake.scm (cmake): Simplify the synopsis.
* gnu/packages/version-control.scm (subversion): Remove "open-source"
  from the description.

gnu: cmake: Update patch to work with new system.

* gnu/packages/patches/cmake-fix-tests.patch: Update to work with -p1.
* gnu/packages/cmake.scm (cmake): Drop patch flag -p0.

gnu: Use the 'patches' field of <origin>.

* gnu/packages/apr.scm,
  gnu/packages/autotools.scm,
  gnu/packages/avahi.scm,
  gnu/packages/cdrom.scm,
  gnu/packages/cmake.scm,
  gnu/packages/cpio.scm,
  gnu/packages/cross-base.scm,
  gnu/packages/emacs.scm,
  gnu/packages/flex.scm,
  gnu/packages/fontutils.scm,
  gnu/packages/glib.scm,
  gnu/packages/grub.scm,
  gnu/packages/guile.scm,
  gnu/packages/idutils.scm,
  gnu/packages/libevent.scm,
  gnu/packages/linux.scm,
  gnu/packages/mail.scm,
  gnu/packages/make-bootstrap.scm,
  gnu/packages/mp3.scm,
  gnu/packages/oggvorbis.scm,
  gnu/packages/pdf.scm,
  gnu/packages/plotutils.scm,
  gnu/packages/qemu.scm,
  gnu/packages/recutils.scm,
  gnu/packages/rush.scm,
  gnu/packages/scheme.scm,
  gnu/packages/system.scm,
  gnu/packages/tcsh.scm,
  gnu/packages/valgrind.scm,
  gnu/packages/vpn.scm,
  gnu/packages/w3m: Use the 'patches' field of <origin> instead of
  adding a patch as input plus using #:patches.

Merge branch 'master' into core-updates

Conflicts:
	Makefile.am
	gnu/packages/base.scm

gnu: Add cmake.

* gnu/packages/cmake.scm: New file.
* gnu/packages/patches/cmake-fix-tests.patch: New file.
* Makefile.am: Add them.