Merge pull request #3 from CVerhoosel/master

Added logical AND operator
Merge pull request #4 from CVerhoosel/master

Added vector_sum (incl. test)
Added installation instructions README
Removed quotation README
Merge pull request #5 from rodyvtu/master

Installation in README
add matvec alias for apply
remove non-c++11-compliant constructs
Merge branch 'master' of https://github.com/nutils/libmatrix
add matrix scalar multiplication, division
add Matrix.build_precon and solve: precon str arg
Merge branch 'master' of https://github.com/nutils/libmatrix
assert converged after solve
add solve tol arg, precon string arg + param args
fix bug in complete func for non-square matrices
add solve: outfreq arg