Code Cleanup

- Relocated longUsage and shortUsage to report.cpp, where they belong,
  which has the positive side effect of allowing all the compiled unit
  tests to link.

src/main.h

@@ -53,8 +53,6 @@ void gatherNextTasks (const TDB&, T&, std::vector <T>&, std::vector <int>&);
 void onChangeCallback ();
 std::string runTaskCommand (int, char**, TDB&, bool gc = true, bool shadow = true);
 std::string runTaskCommand (std::vector <std::string>&, TDB&, bool gc = false, bool shadow = false);
-std::string shortUsage ();
-std::string longUsage ();
 
 // recur.cpp
 void handleRecurrence ();
@@ -91,6 +89,8 @@ int deltaSubstitutions (T&, T&);
 std::string handleEdit ();
 
 // report.cpp
+std::string shortUsage ();
+std::string longUsage ();
 void filterSequence (std::vector<T>&, T&);
 void filter (std::vector<T>&, T&);
 std::string handleInfo ();