Reading and writing

• flc_read(handle, dst, nbytes);
• flc_write(handle, src, nbytes);
• handle: FLC_HANDLE returned from flc_open(...)
• src, dst: may be an array or pointer to structure
• nbytes: size of data block in bytes
• flc_ready(read_handle): returns 1 if data block has been written to since the last time the handle was read