upgrade to md2man 2.0
GH-53: rescue from failed writes to closed clients
Version 19.3.1 (2013-06-07)
GH-55: upgrade listen & rake gem dependencies
Version 19.3.2 (2013-10-29)
rails: set up sqlite3 test DB for parallel testing
rails: also load seeds into memory DB after schema
rails: remove unused capture of rescued exception
coverage: document the use of Ruby 1.9 hash syntax
rename *.markdown file extension to shorter *.md
Version 19.4.0 (2013-11-25)
GH-56: specify license in gemspec for rubygems.org
document sh(1) word splitting in all tork servers
README: use `ps uf` to visualize process hierarchy
must pass mutable local variables into Thread.new

The `icon` local variable would be overwritten (to nil sometimes)
outside of the thread and cause the thread body to silently fail.

see http://stackoverflow.com/q/16745840 for details
make connections to tork subprocesses self-healing

When a tork subprocess terminates, its parent process now replaces it
with a fresh instance.  Thus the tork process tree is now self-healing.
socket files were always deleted: even if not ours

If a tork instance was already running and a new tork instance was
started up in the same directory, then the latter would always delete
the common socket files (currently belonging to the former) upon exit.
drop socket retry logic: self-healing does it now
fail earlier on socket bind: avoid wasted overhead

Before this patch, tork-master(1) would first pay the price of absorbing
the test execution overhead before trying to bind its socket.  In case
of socket bind failure, the process would exit and the overhead wasted.
server: @client is only used by recv() and onwards