Add de_old tokenizer variant without gender-sensitive rules

Introduces a new German tokenizer variant 'de_old' that treats
gender-sensitive forms, separted by `:`, `(`, and `/` as separate
tokens.

With de_old:
- Nutzer:in → Nutzer : in (3 tokens)
- Nutzer/innen → Nutzer / innen (3 tokens)
- Kaufmann/frau → Kaufmann / frau (3 tokens)
- Nutzer(in) → Nutzer ( in ) (4 tokens)

The standard 'de' tokenizer continues to keep these as single tokens.

Includes tests for the new variant.

Change-Id: I1d2af97e92a8af36ac3b04c2807bce8422b85df1
diff --git a/pom.xml b/pom.xml
index c9c1fe3..eec21db 100644
--- a/pom.xml
+++ b/pom.xml
@@ -112,6 +112,19 @@
                             <target>src/main/jflex/fr</target>
                         </configuration>
                     </execution>
+                    <execution>
+                        <id>preprocess for de-trad</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>preprocess</goal>
+                        </goals>
+                        <configuration>
+                            <vars>
+                                <target.language>de_old</target.language>
+                            </vars>
+                            <target>src/main/jflex/de_old</target>
+                        </configuration>
+                    </execution>
                 </executions>
                 <configuration>
                     <sources>src/main/jpc/jflex</sources>