Install pycrypto as develop egg.

Drop ERP5's stack workaround, as pycrypto component is now responsible
for delivering correctly configured egg.

stack/erp5.cfg

@@ -52,6 +52,7 @@ extends =
   ../component/memcached/buildout.cfg
   ../component/mysql-python/buildout.cfg
   ../component/pdftk/buildout.cfg
+  ../component/pycrypto-python/buildout.cfg
   ../component/pysvn-python/buildout.cfg
   ../component/python-2.6/buildout.cfg
   ../component/python-2.7/buildout.cfg
@@ -305,7 +306,7 @@ eggs =
   ${lxml-python:egg}
   ${python-ldap-python:egg}
   ${pysvn-python:egg}
-  pycrypto
+  ${pycrypto-python:egg}
   PyXML
   SOAPpy
   cElementTree
@@ -409,9 +410,6 @@ scripts =
 # Use SlapOS patched zc.buildout
 zc.buildout = 1.5.3-dev-SlapOS-010
 
-# Temporary fix: pycrypto 2.4+ using configure are not buildable
-pycrypto = 2.3
-
 # pin Acquisition and Products.DCWorkflow to Nexedi flavour of eggs
 Acquisition = 2.13.7nxd001
 Products.DCWorkflow = 2.2.3nxd002