split library source code
file and printf
examples
lbu instruction
fix fprintf args
avoid redefine
add str* functions to libs.h
clock_gettime
sys_time
sys_time
more instructions

xori, ori
lhw, swl, ...
be careful with delay slot...
make clean
new dhrystone without floting point
more simple file functions
uint16_t
div, bgtz
message for exit()
ROUND* functions should have type uint32_t
correct time()