Add Polish language (#234)

---------

Co-authored-by: sspanak <doftor.livain@gmail.com>

docs/dictionaries/plWordListReadme.txt

@@ -0,0 +1,15 @@
+Polish Dictionary (Pl.dic).
+
+  This version of Polish dictionary was compiled
+  by Włodzimierz Macewicz <W.Macewicz@ia.pw.edu.pl>
+
+  Build: 02.01.1999
+  by W.Macewicz <W.Macewicz@ia.pw.edu.pl>
+
+  The dictionary has over 440K words and it needs about 5MB
+  of disc space. It includes almost all the words from
+  the Mazovia dictionary
+
+  ftp://iapw.ia.pw.edu.pl/sys/pub/slownik
+
+Word Frequencies obtained from: https://github.com/openboard-team/openboard/blob/master/dictionaries/pl_wordlist.combined.gz

src/io/github/sspanak/tt9/languages/LanguageCollection.java

@@ -32,6 +32,7 @@ public class LanguageCollection {
 			Indonesian.class,
 			Italian.class,
 			Norwegian.class,
+			Polish.class,
 			Russian.class,
 			Spanish.class,
 			Swedish.class,

src/io/github/sspanak/tt9/languages/definitions/Polish.java

@@ -0,0 +1,22 @@
+package io.github.sspanak.tt9.languages.definitions;
+
+import java.util.Arrays;
+import java.util.Locale;
+
+public class Polish extends English {
+	public Polish() {
+		super();
+
+		locale = new Locale("pl","PL");
+		dictionaryFile = "pl-utf8.csv";
+
+		isPunctuationPartOfWords = false;
+
+		characterMap.get(2).addAll(Arrays.asList("ą", "ć"));
+		characterMap.get(3).add("ę");
+		characterMap.get(5).add("ł");
+		characterMap.get(6).addAll(Arrays.asList("ó", "ń"));
+		characterMap.get(7).add("ś");
+		characterMap.get(9).addAll(Arrays.asList("ź", "ż"));
+	}
+}