Sorting

- Sorting implemented using a non-relocatable task list, a stable
  sort, and type-specific comparisons.

src/CMakeLists.txt

@@ -18,9 +18,9 @@ set (task_SRCS API.cpp API.h Att.cpp Att.h Cmd.cpp Cmd.h Color.cpp Color.h
                TransportCurl.h Tree.cpp Tree.h burndown.cpp command.cpp
                custom.cpp dependency.cpp diag.cpp edit.cpp export.cpp
                history.cpp i18n.h import.cpp interactive.cpp recur.cpp
-               report.cpp rules.cpp rx.cpp rx.h text.cpp text.h utf8.cpp utf8.h
-               util.cpp util.h Uri.cpp Uri.h Variant.cpp Variant.h View.cpp
-               View.h)
+               report.cpp rules.cpp rx.cpp rx.h sort.cpp text.cpp text.h
+               utf8.cpp utf8.h util.cpp util.h Uri.cpp Uri.h Variant.cpp
+               Variant.h View.cpp View.h)
 
 add_library (task STATIC ${task_SRCS})
 add_executable (task_executable main.cpp)