m4ri calls exit

[Alexander Dreyer]

Hi! While updating fall-back m4ri in PolyBoRi I recognized that the recent update contains a call of {{{exit(-1)}}} . This should be avoided in libraries, because the calling program will not be able to hable this accordingly. I suggest to use {{{abort()}}} instead. See my attached patch.

[Martin Albrecht]

holy shit, how did that one get through! Thanks, I've applied your patch! See 1c327bc3cdc2