post-chimeric detection operation: spliting

[natir]

If read as a chimera remove not covered region split read on this region.

[natir]

branch issue_16 contains code to solve this issue.

Todo:

• [x] check size before try to substring
• [x] code factorization

[natir]

19154aa61e63098ab5a4feac46d373b0186d4b21 solve major part of this issue. But I want wait to close this before the code factorisation isn't increase.