TODO for pddp
  * pddplink:
    . standardize server's root directory (use $help_directory from pd.tk?)

DONE for pddp

alpha2
  * loading tcl scripts through "package require pddp":
    . storing them in an immediate subdirectory of the path of pddplink's binary
    . storing a hand-crafted pkgIndex.tcl there
    . pddplink's setup appends the path of its binary to tcl's "auto_path"
  * pddpserver asks for auto-assigning its port first, then starts
    incrementing from 32768
  * pddplink's appearance controlled with creation options (an option switch
    is any symbol starting from '-' followed by a letter)
  * options currently recognized:
    . "-box" (standard object box)
    . "-text" followed by any number of non-option atoms (body text)
  * nonboxed version (default) has a custom widgetbehavior, which is a thin
    layer on top of the standard text widgetbehavior (using all rtext routines),
    so that merging into core Pd, as a new object type, T_LINK, would be easy.

alpha1
  * prototype versions of the external "pddplink" and two pd-gui extensions
    "pddpserver.tcl", "pddpclient.tcl"