Use XDG_CONFIG_HOME for storing the config if ~/.DMDirc/ does not exist.

Fixes issue 3097

Change-Id: I3e85e23908421bc6631718dfd74027acb61a3249
Reviewed-on: http://gerrit.dmdirc.com/92
Reviewed-by: Gregory Holmes <greboid@dmdirc.com>
Tested-by: Gregory Holmes <greboid@dmdirc.com>

launcher/unix/DMDirc.sh

@@ -172,9 +172,16 @@ fi;
 
 # Check for some CLI params
 if [ "${ISOSX}" = "1" ]; then
-	profiledir="${HOME}/Library/Preferences/DMDirc"
+	profiledir="${HOME}/Library/Preferences/DMDirc/"
 else
 	profiledir="${HOME}/.DMDirc/"
+	if [ ! -d "${profiledir}" ]; then
+		profiledir="${XDG_CONFIG_HOME}"
+		if [ "${profiledir}" = "" ]; then
+			profiledir="${HOME}/.config"
+		fi;
+		profiledir="${profiledir}/DMDirc/"
+	fi;
 fi;
 
 USEPROFILE=1;

src/com/dmdirc/Main.java

@@ -332,6 +332,14 @@ public final class Main {
                 }
             } else {
                 configdir = System.getProperty("user.home") + fs + ".DMDirc" + fs;
+                final File testFile = new File(configdir);
+                if (!testFile.exists()) {
+                    final String configHome = System.getenv("XDG_CONFIG_HOME");
+                    configdir = configHome.isEmpty() ?
+                        System.getProperty("user.home") + fs + ".config" + fs :
+                        configHome;
+                    configdir += fs + "DMDirc" + fs;
+                }
             }
         }