Documentation update

- Removed DEVELOPERS file.  Not only does it contain obsolete content,
  it doesn't really provide much help.  Hopefully developers will hit
  the online forums for this kind of help.

DEVELOPERS

@@ -1,23 +0,0 @@
-Developers may wish to change task, and here is a high-level guide to the files
-included.
-
-  task.{cpp,h}     Implements main, high level processing.
-  command.cpp      Implements all non-report task commands.
-  report.cpp       Implements all task reports.
-  parse.cpp        Parses the command line.
-  TDB.{cpp,h}      The task database, performs all file I/O.
-  T.{cpp,h}        Represents a single task - parses a record from TDB, and also
-                   composes record for TDB.  Provides accessors for tasks.
-  Grid.{cpp,h}     Implements a sparse 2D array, provides data storage for the
-                   Table object.
-  Table.{cpp,h}    Implements tabular data rendering, wrapping etc.
-  Config.{cpp,h}   Implements a reader for the .taskrc file.
-  Date.{cpp,h}     General date class for the time_t type.
-  Duration.{cpp,h} General duration class for time deltas.
-  text.cpp         Text manipulation functions.
-  util.cpp         General utility functions.
-  color.cpp        Color support functions.
-  rules.cpp        Auto-colorization rules.
-
-Please send bugs, patches to task@beckingham.net
-