Feature Pulled

- Removed the feature that allows commands to be piped in to stdin,
  and appended to any existing command line.  This feature is
  conditionally compiled, controlled by the FEATURE_STDIN define in
  main.h
- Many unit tests contained "echo '-- y'", and now use "echo 'y'"
  because the '--' is no longer supported on stdin.
- Thanks to the IRC team for testing, including Bryce Harrington,
  Sam Stuck, Owen Clarke, Greg Grossmeier.

ChangeLog

@@ -6,10 +6,7 @@
 # Untracked Features, biggest first.
  + autoconf eliminated.
  + New 'ids' command that returns a filtered set of task ID numbers, instead
-   of the actual tasks.  Similarly there is a 'uuids' commands.  For advanced
-   pipeline use.
- + Now supplements the command line with data read from standard input, which
-   allows commands like:  echo 'add Pay the bills' | task
+   of the actual tasks.  Similarly there is a 'uuids' commands.
  + Corrected sorting to use std::stable_sort instead of std::sort, which is not
    guaranteed stable (thanks to Stefan Hacker).
  + Enhanced diagnostics command.