Using structure FileDesc to transport files information instead of 'struct tree_descr' of libfs becausa FileDesc we can change if needed.
Implemented function do add file do dcache.
Added test tcpserver while our daemon is not working properly. 'tcpserver.c' is based on code of http://www.cs.cmu.edu/afs/cs/academic/class/15213-f99/www/class26/tcpserver.c