initialisation of files
finished ptw struct
begun work on open_ptw_file()
moved tests to dedicated file
moved tests to dedicated file and included ptw.c
finished writing basic header information dump test
added mem_errors struct to ptw_file, possibly superfluous
about halfway through open_ptw_file()
added space for null terminator to key_frames_in_file
finished open_ptw_file()
made file_ptr print as unsigned
stop test.c referencing null pointers on memory errors
Merge branch 'master' of github.com:jakelishman/ptw-tools