This PR is extension of #117.
In that PR functionality of reading compressed files was added. We used boost::filtering streams to read the compressed files.
Boost filtering streams delayed the output.
Using boost for compressed files was fine. but using it for normal files was just delayed the output uselessly.
So now I have used normal istream for uncompressed file and boost filtering streams for compressed ones.
This PR is extension of #117. In that PR functionality of reading compressed files was added. We used boost::filtering streams to read the compressed files. Boost filtering streams delayed the output. Using boost for compressed files was fine. but using it for normal files was just delayed the output uselessly. So now I have used normal istream for uncompressed file and boost filtering streams for compressed ones.