Loosen types on mmap on unix

In particular make it work for isa(fd,RawFD) and offset any integer type (there is a lot of precedent for allowing any Integer Rather than just FileOffset. In particular most of the io.jl methods do this).
Merge remote-tracking branch 'origin/kf/mmap'
Make RawFD a noop for passed in RawFD

this can happen in the Windows mmap code and it would be much nicer if it
just worked.
parse sqrt symbol (√) as a unary operator
Fix clean-arpack as well
More better way of doing things
Fix function definition
Update deps checksums for new arpack versions
Add ASCII-art and nicer hash printing when it's long