src: improve the error messages
src: add Object PartialPivLU
src: add instance method 'permutationP()' of PartialPivLU
test: add constructor testings of PartialPivLU
test: add instance method 'permutationP()' of PartialPivLU
readme: add PartialPivLU and constractor api
readme: add instance method 'permutationP()' api of PartialPivLU
test: update 'PartialPivLU.permutationP()' testing
src: add instance method 'matrixL()' of PartialPivLU
test: add instance method 'matrixL()' testing of PartialPivLU
readme: add instance method 'matrixL()' api of PartialPivLU
src: add instance method 'matrixU()' of PartialPivLU
test: add instance method 'matrixU()' testing of PartialPivLU
readme: add instance method 'matrixU()' api of PartialPivLU
readme: update constructor of 'PartialPivLU' api
src: add instance method 'solve()' of PartialPivLU
test: add instance method 'solve()' testings of PartialPivLU
readme: fix some mistake
readme: add instance method 'solve()' api of PartialPivLU
src: add instance method 'partialPivLu()'