Merge pull request #627 from mohamed-barakat/devel

enhanced Pullback for matrices

Merge pull request #626 from mohamed-barakat/devel

temporarily disable testing with GAP master until GAP 4.15 is released

Merge pull request #624 from mohamed-barakat/ZeroRows_ZeroColumns

improved/fixed immediate method for ZeroRows/ZeroColumns

Merge pull request #623 from mohamed-barakat/devel

installed LastOp for IsLazyHListRep

Merge pull request #622 from mohamed-barakat/devel

bumped versions

Merge pull request #622 from mohamed-barakat/devel

bumped versions

Merge pull request #620 from mohamed-barakat/devel

Merge pull request #618 from mohamed-barakat/AutoDoc

Merge pull request #617 from mohamed-barakat/RationalShiftAlgebra

d&i *RationalShiftAlgebra

Merge pull request #617 from mohamed-barakat/RationalShiftAlgebra

d&i *RationalShiftAlgebra