Config module takes care of the configuration file 'config.in'. It
reads the file line by line, parsing each line and extracting the name
and value of parameter. Then it substitutes the parameter with a new
value.
Error module handles error, warning and informative messages. So far it
only prints information on the screen.
There is some improvments for comments formating as well.
Block structure has been implemented. Blocks contain pointers to the next
and previous blocks. This easily allows to create block lists. Two
functions are implemented, one for creating initial structure of blocks
with lists, and the second for destroying all blocks from the list.
File 'blocks.F90' has been added to makefile too.
