Nickname regex configurable

Essentials/src/main/java/com/earth2me/essentials/ISettings.java

@@ -424,6 +424,8 @@ public interface ISettings extends IConf {
 
     boolean showZeroBaltop();
 
+    String getNickRegex();
+
     BigDecimal getMultiplier(final User user);
 
     int getMaxItemLore();

Essentials/src/main/java/com/earth2me/essentials/Settings.java

@@ -2120,6 +2120,11 @@ public boolean showZeroBaltop() {
         return config.getBoolean("show-zero-baltop", true);
     }
 
+    @Override
+    public String getNickRegex() {
+        return config.getString("allowed-nicks-regex", "^[a-zA-Z_0-9§]+$");
+    }
+
     @Override
     public BigDecimal getMultiplier(final User user) {
         BigDecimal multiplier = defaultMultiplier;

Essentials/src/main/java/com/earth2me/essentials/commands/Commandnick.java

@@ -63,7 +63,7 @@ protected void updatePlayer(final Server server, final CommandSource sender, fin
 
     private String formatNickname(final User user, final String nick) throws Exception {
         final String newNick = user == null ? FormatUtil.replaceFormat(nick) : FormatUtil.formatString(user, "essentials.nick", nick);
-        if (!newNick.matches("^[a-zA-Z_0-9" + ChatColor.COLOR_CHAR + "]+$") && user != null && !user.isAuthorized("essentials.nick.allowunsafe")) {
+        if (!newNick.matches(ess.getSettings().getNickRegex()) && user != null && !user.isAuthorized("essentials.nick.allowunsafe")) {
             throw new TranslatableException("nickNamesAlpha");
         } else if (getNickLength(newNick) > ess.getSettings().getMaxNickLength()) {
             throw new TranslatableException("nickTooLong");

Essentials/src/main/resources/config.yml

@@ -33,6 +33,11 @@ nickname-prefix: '~'
 # The maximum length allowed in nicknames. The nickname prefix is not included in this.
 max-nick-length: 15
 
+# The regex pattern used to determine if a requested nickname should be allowed for use.
+# If the a request nickname does not matched this pattern, the nickname will be rejected.
+# Users with essentials.nick.allowunsafe will be able to bypass this check.
+allowed-nicks-regex: '^[a-zA-Z_0-9§]+$'
+
 # A list of phrases that cannot be used in nicknames. You can include regular expressions here.
 # Users with essentials.nick.blacklist.bypass will be able to bypass this filter.
 nick-blacklist: