Add scale(A::Array, B::Number)
More cases dispatch to BLAS scal!
close #2689
Delete examples/{graph.jl,heap.jl} (#2598)

Heaps are added in #2920
Graphs.jl has sophisticated graph functionality.
Remove examples/RMT now that we have the RandomMatrices.jl package
Add whitespace to jl_show error message.
Logical indexing for sparse matrices.
close #1994