GUAC-1138 Implemented global active session filter against name, username, and remote host.

guacamole/src/main/webapp/translations/en_US.json

@@ -243,6 +243,8 @@
         "DIALOG_HEADER_CONFIRM_DELETE" : "Kill Sessions",
         "DIALOG_HEADER_ERROR"          : "Error",
         
+        "FIELD_PLACEHOLDER_FILTER" : "Filter",
+        
         "HELP_SESSIONS" : "All currently-active Guacamole sessions are listed here. If you wish to kill one or more sessions, check the box next to those sessions and click \"Kill Sessions\". Killing a session will immediately disconnect the user from the associated connection.",
         
         "INFO_NO_SESSIONS" : "No active sessions",