Sort order of samples in outfile

[tetedange13]

Order of samples in output file is determined by os.listdir() (L359) and is not very intuitive (not lexicographic)

Could be nice :

• At least to have something more intuitive (eg: similar to ls)
• Better to have samples "version-sorted" (like with sort -V / --version-sort = CSG001 > CSG002 > CSG003 > ... > CSG010 ...)
• Even better : controlable samples sort order

Could be through a new parameter such as -l / --list with a list of files (and mutually exclusive with current -i / --input /path/to/dir)
=> This way we could for example keep same order as in SampleSheet

Thanks a bunch !
Felix.