Gccov

- fix pileup coverm bug.

- Fix entry point bug.

- update dependency biosut.
- re-structured whole project.

add coverm to caculate coverage of references.

For this v0.03 release, There are majorly two updates:

1. Added an option to scaling the dots or not. It will scale dots according the length of each reference if you choose to scale
2. Made dots fancy like bubbles.