extract method from main (update environment in child process)
extract method from main (parsing command line arguments)
added changelog file
bump up version number to 1.2
pin down the desired config file
get rid of debug flag from output config

debug is represented by the non existing config (null ptr)
rename output config to output filter
rename command config to commands
split output handle to filter and output stream related parts
source file filtering signature simplified
filter went to separate module
filter is on the heap memory
deallocation of memory is common in child and parent process
printing known compilers/extensions no longer supported
rename library loading flag from -b to -l
filter type declaration became hidden internal
use regexp to match compiler and source file in filter
make fewer regex which covers the same set of compilers and extensions
cancel parameter list implemented as regex
cosmetic changes on filter implementation