Generate KeyboardLabelsSet from donottranslate-more-keys.xml

This change introduces makelabel tool that reads all languages'
donottranslate-more-keys and generate KeyboardLabelsSet.java source
file. The makelabel command must be invoked prior to compile LatinIME.

Change-Id: I7515c7919c535e30f9c80a37bdc831d0f682cd43
diff --git a/java/res/xml/rowkeys_qwertz3.xml b/java/res/xml/rowkeys_qwertz3.xml
index d37cee6..e969665 100644
--- a/java/res/xml/rowkeys_qwertz3.xml
+++ b/java/res/xml/rowkeys_qwertz3.xml
@@ -23,20 +23,20 @@
 >
     <Key
         latin:keyLabel="y"
-        latin:moreKeys="@string/more_keys_for_y" />
+        latin:moreKeys="!label/more_keys_for_y" />
     <Key
         latin:keyLabel="x" />
     <Key
         latin:keyLabel="c"
-        latin:moreKeys="@string/more_keys_for_c" />
+        latin:moreKeys="!label/more_keys_for_c" />
     <Key
         latin:keyLabel="v"
-        latin:moreKeys="@string/more_keys_for_v" />
+        latin:moreKeys="!label/more_keys_for_v" />
     <Key
         latin:keyLabel="b" />
     <Key
         latin:keyLabel="n"
-        latin:moreKeys="@string/more_keys_for_n" />
+        latin:moreKeys="!label/more_keys_for_n" />
     <Key
         latin:keyLabel="m" />
 </merge>