use sed -r instead of -E when using GNU sed

[Un1q32]

sed -r and -E do the same thing, but sed -E is the portable version that works with all versions of sed, however some old versions of GNU sed only support -r, a workaround is to check if we're running GNU sed, and use -r if we are

[Un1q32]

bump

[Un1q32]

@BKasin can you try the latest commit, I reworked it into a wrapper function that replaces the arguements if sed is GNU sed, should be completely transparent so nobody has to remember to add $sed_ext to every sed command from now on

[catumin]

Will do.

[hykilpikonna]

Nice fix, thanks!

And @BKasin thank you so much for the detailed testing!