Adding support for Archlinux and Slackware in fallback

In some cases Archlinux and Slackware is not detected by
platform.dist(). This should solve the issue.

lib/ansible/module_utils/facts.py

@@ -97,6 +97,7 @@ class Facts(object):
     # For the most part, we assume that platform.dist() will tell the truth.
     # This is the fallback to handle unknowns or exceptions
     OSDIST_LIST = ( ('/etc/oracle-release', 'OracleLinux'),
+                    ('/etc/slackware-version', 'Slackware'),
                     ('/etc/redhat-release', 'RedHat'),
                     ('/etc/vmware-release', 'VMwareESX'),
                     ('/etc/openwrt_release', 'OpenWrt'),
@@ -255,7 +256,7 @@ class Facts(object):
             RedHat = 'RedHat', Fedora = 'RedHat', CentOS = 'RedHat', Scientific = 'RedHat',
             SLC = 'RedHat', Ascendos = 'RedHat', CloudLinux = 'RedHat', PSBM = 'RedHat',
             OracleLinux = 'RedHat', OVS = 'RedHat', OEL = 'RedHat', Amazon = 'RedHat',
-            XenServer = 'RedHat', Ubuntu = 'Debian', Debian = 'Debian', Raspbian = 'Debian', SLES = 'Suse',
+            XenServer = 'RedHat', Ubuntu = 'Debian', Debian = 'Debian', Raspbian = 'Debian', Slackware = 'Slackware', SLES = 'Suse',
             SLED = 'Suse', openSUSE = 'Suse', SuSE = 'Suse', Gentoo = 'Gentoo', Funtoo = 'Gentoo',
             Archlinux = 'Archlinux', Mandriva = 'Mandrake', Mandrake = 'Mandrake',
             Solaris = 'Solaris', Nexenta = 'Solaris', OmniOS = 'Solaris', OpenIndiana = 'Solaris',
@@ -314,6 +315,21 @@ class Facts(object):
                             # Once we determine the value is one of these distros
                             # we trust the values are always correct
                             break
+                        elif name == 'Archlinux':
+                            data = get_file_content(path)
+                            if 'Arch Linux' in data:
+                                self.facts['distribution'] = name
+                            else:
+                                self.facts['distribution'] = data.split()[0]
+                            break  
+                        elif name == 'Slackware':
+                            data = get_file_content(path)
+                            if 'Slackware' in data:
+                                self.facts['distribution'] = name
+                                version = re.findall('\w+[.]\w+', data)
+                                if version:
+                                    self.facts['distribution_version'] = version[0]
+                            break      
                         elif name == 'OracleLinux':
                             data = get_file_content(path)
                             if 'Oracle Linux' in data: