Task Data Parsing

- Improved the handling when parsing blank lines and empty task in the data, so
  that instead of the message:

    Taskwarrior no longer supports file format 1, originally used between 27
    November 2006 and 31 December 2007.

  We now see:

    Unrecognized Taskwarrior file format or blank line in data.

- Merged t2.t.cpp into t.t.cpp.

test/.gitignore

@@ -20,7 +20,6 @@ msg.t
 nibbler.t
 rx.t
 t.t
-t2.t
 t3.t
 taskmod.t
 tdb2.t