Rename known-mean variants to stdm and varm.
Drop "corrected" flag.
Adding dim/region versions of mean, var, and std.
add Notepad++ support for Julia
Test and doc updates for stdm/varm.
Fix concatenation of string and char in splitdir

This fixes:
julia> dirname("/tmp")
ERROR: no method *(ASCIIString,Char)
 in splitdir at path.jl:32
 in dirname at path.jl:37

We may want to consider getting rid of the remaining * concatenations
in path.jl, but in brief tests I was not able to trigger errors. So
this is conservative.
Use strncmp in begins_with for ByteStrings

On my machine this is ~2.5x faster. It's also trivial to generalize to
Array{Uint8,1}. This can be convenient in situations like testing for
magic bytes in files, where you might want to read into a Uint8 buffer
but test against a string.
Merge pull request #2563 from wlbksy/master

add Notepad++ support for Julia
Merge pull request #2561 from blakejohnson/stats-dim-args

varm/stdm and stats dimension arguments (closes #2265)
examples/modint.jl: make the ModInt type immutable.
Pkg: make Pkg.Resolve interface purely functional.

This is a first step towards refactoring Pkg in such a way that it
can actually be tested. Since this is now purely functional, it can
be tested without needing to have git repos or any other Pkg stuff.