ejabberd 0.9 : virtual hosting and shared roster support

There's a new ejabberd version with virtual hosting and shared roster support:

Important comments:

On the web administration, you must use:
- name: the full JID of an administrator on that Jabber server. You can give admin privileges to any Jabber account (on this Jabber server or any other) on ejabberd.cfg.
- password: the password of that Jabber account.
If you upgrade from previous ejabberd, you must replace on your old ejabberd.cfg
```
{host, "myjabber.mycompany.com"}.
```
with
```
{hosts, ["myjabber.mycompany.com"]}.
```

Quick Shared Roster guide:

To enable the module, add at the beginning of 'modules' section in your ejabberd.cfg:
```
{mod_shared_roster, []},
```
Restart ejabberd.
Go to the Webadmin. If the module is correctly enabled there'll be a link 'Shared Roster'.
Create a new group with identifier: test
It will be added to the list of groups. Click on it.
Here you will configure that group. Let's check the formulary:
- Name: is the nice name of the group on the user's rosters. Example: Test Group
- Description: is a description. Example: This group is just for testing
- Members: list of members of the group, one on each line. Example:
```
user1@localhost
user2@localhost
user3@localhost
```
- Displayed Groups: Put here the groop identification: test
Login with any of the users defined on the group. He will have a virtual roster group with the group members.

User login