gnu: wpa-supplicant: Add security fixes.

* gnu/packages/patches/wpa-supplicant-2015-2-fix.patch,
  gnu/packages/patches/wpa-supplicant-2015-3-fix.patch,
  gnu/packages/patches/wpa-supplicant-2015-4-fix-pt1.patch,
  gnu/packages/patches/wpa-supplicant-2015-4-fix-pt2.patch,
  gnu/packages/patches/wpa-supplicant-2015-4-fix-pt3.patch,
  gnu/packages/patches/wpa-supplicant-2015-4-fix-pt4.patch,
  gnu/packages/patches/wpa-supplicant-2015-4-fix-pt5.patch: New files.
* gnu-system.am (dist_patch_DATA): Add them.
* gnu/packages/admin.scm (wpa-supplicant-light)[source]: Add patches.