Enhancements, Bug Fix

- Removed obsolete usage.html page.
- Added filterSequence helper function to subset tasks to the affected
  sequence of tasks.
- Added series of helper functions to facilitate applying modifications
  to tasks, allowing more commands the ability to modify tasks in all
  ways.
- Added calls to helper functions for append and modify commands.
- Fixed bug that would mistakenly validate the configuration variable
  "bcd" if there was a valid "abcd", "bcde" or "abcde" configuration
  variable.
- Made the messages generated by task after a command is complete
  more verbose and consistent across all commands.
- Fixed bug that caused the ghistory command to skip months where no
  tasks were added, but were deleted or done.  This is the same bug
  that was fixed in 1.6.0 for the history report.  So much for cut
  and paste.
- Allowed all commands that take an ID to now operate on a sequence.

ChangeLog

@@ -8,6 +8,10 @@
    Charles Yun).
  + Now writes a sample "defaultwidth" configuration variable to the default
    .taskrc file (thanks to T. Charles Yun).
+ + Task allows commands that require an ID to now be given a sequence, which
+   is a set of IDs.  This allows commands like "task delete 1 2 5-10,12".
+ + Fixed bug in the ghistory report, which caused it to only show a new
+   month if a task was added during that month.
 
 ------ old releases ------------------------------