Added some todo

In respose to the fact that I had to write a custom lso file, I would
like to make the toolchain more flexible by allowing users specify their
own library
Fixed a compilation warning
modified the design to use env['CONFIG_FILE']

instead of extrapolating the config file from the environment before
calling the 'read_config' I changed it so that I feed the env into the
read config function and the function is the only point where this
configuration data is read.