core: Fix possible starvation when handling multiple clients

Instead of reading from a client fd until there is no longer data,
have a max number of messages that the daemon processes in one poll.
Then return with a status indicating more messages are available to be
processed and set the poll to timeout to 0 in order to quickly return
to processing new data from clients.
Switch to configurator

Configurator is great.  It replaces the usage of constants.[ch] to a
flexible system.  It also encapsulates the ini parser functionality to
one spot.  The tests are changed to more sensible directories.

Configurator introduces order of precedence for configuration items.
1) things added through the command line with buxton_add_cmd_line()
2) things in the environment
3) things in the conf file
4) compiled in defaults

Configurator also adds a section to the configuration file to store
these values.

Configurator improves your day and brightens your future

Signed-off-by: Michael Leibowitz <michael.leibowitz@intel.com>