Pointer cleanup (#242)

- Made greater use of smart pointers, eliminating many instances of manual memory management
- Do not use pointers at all for many non-polymorphic classes
- Assorted other code cleanup

translations/glabels_C.ts

@@ -167,17 +167,6 @@
         <translation type="unfinished"></translation>
     </message>
 </context>
-<context>
-    <name>Db</name>
-    <message>
-        <source>Other</source>
-        <translation type="unfinished"></translation>
-    </message>
-    <message>
-        <source>Roll</source>
-        <translation type="unfinished"></translation>
-    </message>
-</context>
 <context>
     <name>EditVariableDialog</name>
     <message>