Add grid settings to preferences (#224)

- Allow origin to be either at the top-left corner or center of label (#174)
- For non-rectangular labels (cd, round, etc.) the origin will still
  always be at the center of the label.
- User controllable grid spacing

translations/glabels_C.ts

@@ -528,6 +528,34 @@
         <source>Picas</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>Grid</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Configure grid behavior.</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Origin</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Center</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Spacing</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Top left corner</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <source>Reset</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>PrintView</name>