Add a unit test to subset limiting via a regex, and some doc in man

page.

docs/man/man1/ansible.1

@@ -156,6 +156,11 @@ is mostly useful for crontab or kickstarts\&.
 .RS 4
 Further limits the selected host/group patterns\&.
 .RE
+.PP
+\fB\-l\fR \fI~REGEX\fR, \fB\-\-limit=\fR\fI~REGEX\fR
+.RS 4
+Further limits hosts with a regex pattern\&.
+.RE
 .SH "INVENTORY"
 .sp
 Ansible stores the hosts it can potentially operate on in an inventory file\&. The syntax is one host per line\&. Groups headers are allowed and are included on their own line, enclosed in square brackets that start the line\&.

test/TestInventory.py

@@ -158,6 +158,14 @@ class TestInventory(unittest.TestCase):
         print "EXPECTED=%s" % sorted(expected_hosts)
         assert sorted(hosts) == sorted(expected_hosts)
 
+    def test_regex_exclude(self):
+        inventory = self.complex_inventory()
+        hosts = inventory.list_hosts("~rtp_[ac]")
+        expected_hosts = ['rtp_a', 'rtp_c']
+        print "HOSTS=%s" % sorted(hosts)
+        print "EXPECTED=%s" % sorted(expected_hosts)
+        assert sorted(hosts) == sorted(expected_hosts)
+
     def test_complex_enumeration(self):