Fix acl module doc and error messages

- Fix typos in module doc
- Provide clearer error message when entry and etype are both missing

library/files/acl

@@ -95,7 +95,7 @@ EXAMPLES = '''
 - acl: name=/etc/foo.d entity=joe etype=user permissions=rw default=yes state=present
 
 # Same as previous but using entry shorthand
-- acl: name=/etc/foo.d entrty="default:user:joe:rw-" state=present
+- acl: name=/etc/foo.d entry="default:user:joe:rw-" state=present
 
 # Obtain the acl for a specific file
 - acl: name=/etc/foo.conf
@@ -218,7 +218,7 @@ def main():
 
     if state in ['present','absent']:
         if  not entry and not etype:
-            module.fail_json(msg="%s requries to have ither either etype and permissions or entry to be set" % state)
+            module.fail_json(msg="%s requires either etype and permissions or just entry be set" % state)
 
     if entry:
         if etype  or entity  or permissions: