* plb: finished migration of human to pthreadwrapper_{init|deinit}
  * plb: moved human set up into pthreadwrapper_{init|deinit}
  * plb: checkpointing better commenting and human task
  * plb: checkpointing remaining global replacements, all done now
  * plb: checkpointing remaining global replacements, all done now
  * plb: checkpointing some global replacements prior to more
  * plb: checkpointing some global replacements prior to more
  * plb: corrected iorelay/connect/disconnect mutex management
  * plb: got some other tasks working
  * plb: added mutex to allow iorelay to tell main thread that it may disconnect stuff
  * plb: checkpointing development
  * plb: trying to fix fds reassessment code
  * plb: removed unused variables and most unused code
  * plb: added files missing from previous commit
  * plb: changes to main() to allow calling any predefined model (i.e. a task talking to a task)
  * plb: massive overhaul of relay method, with consequent changes everywhere
  * plb: stripped some more 2s from function names, removed raw code as seems not to be
    needed, added dot and quitter tasks (quitter will require more extensive work), commiting beforehand
  * plb: deleted broken version, removed *2* suffix from working version
  * plb: checked that human->relay->sink and clock->relay->human worked as well as clock->relay->sink
  * plb: when adding alias to table, check not already present
  * plb: iorelay closes its fds *if* they're ptys (proper implementation)
  * plb: iorelay closes its fds *if* they're ptys (cheat's implementation for now)
  * plb: reimplemented "I'm initialised" signaling using pthread mutex
  * plb: human task now included
  * plb: ongoing code alignment (cosmetic changes)
  * plb: ongoing code alignment (completed change to original setattr/getattr functions)
  * plb: ongoing code alignment (more change to original setattr/getattr functions)
  * plb: ongoing code alignment (more change to original setattr/getattr functions)
  * plb: ongoing code alignment (partial change to original setattr/getattr functions)
  * plb: ongoing code alignment (just before copying pthreadwrapper_{set,get}attr() over
  * plb: beginnings of alignment of code between working and non-working versions
  * plb: more aligned comments in code
  * plb: minor tidying
  * plb: committed working plb2 test program, which I will now gradually add plb's features to, to 
    see when it breaks
  * plb: ongoing development (investigating missing io to sink; not working but want checkpoint)
  * plb: ongoing development (investigating missing io to sink)
  * plb: ongoing development (investigating missing io to sink)
  * plb: ongoing development (investigating missing io to sink)
  * plb: ongoing development (iorelay is dedicated thread)
  * plb: ongoing development (solved the clock-speaks-3-times-but-sink-only-hears-2-or-3-times problem)
  * plb: ongoing development (added iorelayer ptwid, though not running in dedicated thread yet)
  * plb: updated Makefile to stop generating .gch files
  * plb: ongoing development (prior to introduction of connections table)
  * plb: updated makefile to generate header dependencies automatically
  * plb: ongoing development (my_clock thread working)
  * plb: ongoing development
  * plb: ongoing development
  * plb: created module