eol: ensure the eol extensions is loaded when hooks run

Similar to the change we did to the 'acl' extensions, we want to make sure the
config items are registered before we run the hooks.

hgext/eol.py

@@ -244,8 +244,22 b' def parseeol(ui, repo, nodes):'
                   "at %s: %s\n") % (inst.args[1], inst.args[0]))
     return None
 
+def ensureenabled(ui):
+    """make sure the extension is enabled when used as hook
+
+    When eol is used through hooks, the extension is never formally loaded and
+    enabled. This has some side effect, for example the config declaration is
+    never loaded. This function ensure the extension is enabled when running
+    hooks.
+    """
+    if 'eol' in ui._knownconfig:
+        return
+    ui.setconfig('extensions', 'eol', '', source='internal')
+    extensions.loadall(ui, ['eol'])
+
 def _checkhook(ui, repo, node, headsonly):
     # Get revisions to check and touched files at the same time
+    ensureenabled(ui)
     files = set()
     revs = set()
     for rev in xrange(repo[node].rev(), len(repo)):