wendelin.core: Add way to run tests

Just like with pygolang and zodbtools add way to run wendelin.core tests
via nxdtest with test instance organized with help of stack/nxdtest.cfg

Test agains ZODB4 and ZODB5 for the reasons explained in previous patch.

Wendelin.core already had [wendelin.core-dev], so we only have to add
test*.cfg in this patch.

component/wendelin.core/test-common.cfg

+# SlapOS software release to test wendelin.core on Nexedi testing infrastructure.
+# Common parts.
+
+[buildout]
+extends =
+# test*.cfg first extend from neoppod/software<ZODB-flavour>.cfg to use
+# appropriate ZODB and versions of other components.
+
+    ../pytest/buildout.cfg
+    ../gdb/buildout.cfg
+    ../../stack/nxdtest.cfg
+    buildout.cfg
+
+parts =
+# keep neoppod first and in parts so that ZODB is built correctly
+    neoppod
+
+    wendelin.core-dev
+
+#   for instance
+    wendelin.core-python
+    slapos-cookbook
+    instance.cfg
+
+
+# bin/python s python interpreter with wendelin.core and all other eggs.
+[wendelin.core-python]
+<= python-interpreter
+eggs =
+    wendelin.core[test]
+    pygolang[pyx.build]
+    neoppod[tests]
+    ZEO[test]
+
+# env.sh for that python to be on $PATH
+[wendelin.core-env.sh]
+recipe   = slapos.recipe.template:jinja2
+rendered = ${buildout:directory}/${:_buildout_section_name_}
+template = inline:
+  export PS1="(wendelin.core-env) $PS1"
+  export PATH=${buildout:bin-directory}:${gdb:location}/bin:$PATH
+
+# instance to run nxdtest.
+[instance.cfg]
+<= jinja2-template
+template = inline:
+  [buildout]
+  extends = ${nxdtest-instance.cfg:rendered}
+
+  [runTestSuite]
+  env.sh  = ${wendelin.core-env.sh:rendered}
+  workdir = ${wendelin.core-repository:location}
+
+
+[versions]
+neoppod = 1.12.0
+
+zope.testrunner = 5.2
+random2 = 1.0.1
+manuel = 1.10.1

component/wendelin.core/test-zodb5.cfg

+# SlapOS software release to test wendelin.core/ZODB5 on Nexedi testing infrastructure.
+
+[buildout]
+extends =
+    ../../stack/erp5/buildout.cfg
+    ../../software/neoppod/software-zodb5.cfg
+    test-common.cfg

component/wendelin.core/test.cfg

+# SlapOS software release to test wendelin.core on Nexedi testing infrastructure.
+
+[buildout]
+extends =
+    ../../stack/erp5/buildout.cfg
+    ../../software/neoppod/software.cfg
+    test-common.cfg