Sample programs using log4c

application_1 -- most basic example of using log4c.  Notice that you
only have to setup the category.  Log4c is more powerful and flexible
if you use the log4crc file to setup the relationship between
category, appender, and formatter.

application_2 -- example of using log4c with custom written appenders
and formatters.  Notice in Makefile.am that the linking for
application_2 includes an additional library.  This is an example of
how you as a user of log4c would add in appenders and formatters.

log4crc -- Notice the specifiers of how the catgories from the two
example applications are wired up to appenders and formatters.  Notice
how when specifying a layout and appender, the type= string must match
the name of the appender/formatter given in the code, but that the
name= can be any name you want.  Try and alter the priority= settings,
the appender and layout settings in log4crc and rerunning the examples
to see how the config affects which error messages will be printed.