Enable networkcache in slapgrid's buildout.

As soon as slapgrid (in slapos.core package) has any package, this package
is passed to used buildout. In this case, beacause of using patched SlapOS
zc.buildout 1.5.3-dev-SlapOS-005, slapos.libnetworkcache will be used.

software/slaprunner/software.cfg

@@ -31,6 +31,7 @@ md5sum = e2cbd8fe7b8e4c7e92a19cd775de0aa6
 
 [eggs]
 eggs +=
+  slapos.libnetworkcache
   slapos.toolbox
   slapos.core
 
@@ -47,6 +48,7 @@ setuptools = 0.6c12dev-r88795
 hexagonit.recipe.cmmi = 1.5.0
 hexagonit.recipe.download = 1.5.0
 plone.recipe.command = 1.1
+slapos.libnetworkcache = 0.2
 
 # Use SlapOS patched zc.buildout
 zc.buildout = 1.5.3-dev-SlapOS-005