MDL-28452 core_user: migrate social profile fields

Create a new profile field type, move all existing content of the fields
'icq', 'skype', 'aim', 'yahoo', 'msn' and 'url' in the mdl_user table to
theses new profile fields if needed.

AMOS BEGIN
MOV [aimid,core],[aimid,courseimage,profilefield_social]
MOV [yahooid,core],[yahooid,profilefield_social]
MOV [skypeid,core],[skypeid,profilefield_social]
MOV [icqnumber,core],[icqnumber,profilefield_social]
MOV [msnid,core],[msnid,profilefield_social]
MOV [webpage,core],[webpage,profilefield_social]
AMOS END

admin/settings/users.php

@@ -196,12 +196,6 @@ if ($hassiteconfig
                              'country' => new lang_string('country'),
                              'moodlenetprofile' => new lang_string('moodlenetprofile', 'user'),
                              'timezone' => new lang_string('timezone'),
-                             'webpage' => new lang_string('webpage'),
-                             'icqnumber' => new lang_string('icqnumber'),
-                             'skypeid' => new lang_string('skypeid'),
-                             'yahooid' => new lang_string('yahooid'),
-                             'aimid' => new lang_string('aimid'),
-                             'msnid' => new lang_string('msnid'),
                              'firstaccess' => new lang_string('firstaccess'),
                              'lastaccess' => new lang_string('lastaccess'),
                              'lastip' => new lang_string('lastip'),