Squashed commit of the following:

commit 48069adf0f
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Tue Nov 27 10:13:08 2012 +0100

    Removing this plugin from this branch.

commit 15400fffe6
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Tue Nov 27 09:53:16 2012 +0100

    Enhance _match function in inventory with regex.
    --limit ~regex could be used to filter hosts or group with a regex.
    Tested on cli and ansible-playbook.

commit 63c1b2e17e
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Tue Nov 27 09:03:41 2012 +0100

    Revert pull request #1684

commit 7c2c6fee3a
Merge: f023a2f dd5a847
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Tue Nov 27 08:52:53 2012 +0100

    Merge remote branch 'upstream/devel' into devel

commit f023a2f3df
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Mon Nov 26 20:52:27 2012 +0100

    Add an inventory plugin to fetch groups and host from our CMDB.

commit c64193b4c6
Author: Gregory Duchatelet <skygreg@gmail.com>
Date:   Mon Nov 26 20:43:30 2012 +0100

    Added possibility to filter hosts from a group, with a regex, separating
    groupname and regex with a ~
    Usage in group pattern: group~filterpattern
    Samples:
    ansible group~server-0[1236] -m ping
    ansible web~proxy -m ping
    ansible web~(proxy|frontend) -m ping

lib/ansible/inventory/__init__.py

@@ -19,6 +19,7 @@
 
 import fnmatch
 import os
+import re
 
 import subprocess
 import ansible.constants as C
@@ -92,6 +93,9 @@ class Inventory(object):
                 raise errors.AnsibleError("YAML inventory support is deprecated in 0.6 and removed in 0.7, see the migration script in examples/scripts in the git checkout")
 
     def _match(self, str, pattern_str):
+        if pattern_str.startswith('~'):
+            return re.search(pattern_str[1:], str)
+        else:
             return fnmatch.fnmatch(str, pattern_str)
 
     def get_hosts(self, pattern="all"):
@@ -164,7 +168,7 @@ class Inventory(object):
         a tuple of (start, stop) or None
         """
 
-        if not "[" in pattern:
+        if not "[" in pattern or pattern.startswith('~'):
             return (pattern, None)
         (first, rest) = pattern.split("[")
         rest = rest.replace("]","")