Pkg.scaffold(dir=<dir>): allow scaffolding with any name elsewhere.

This allows creation of new package scaffolding using the same code
that won't have any interaction with the existing registered or
installed packages as requested by @johnmyleswhite.

base/pkg/scaffold.jl

@@ -4,21 +4,26 @@ using Base.Git, ..Dir, ..Read
 
 function scaffold(
  pkg::String;
- license = nothing,
+ dir::String = "",
+ license::String = "",
  years::Union(Int,String) = readchomp(`date +%Y`),
  authors::String = Git.readchomp(`config --global --get user.name`),
 )
- license === nothing && error("""
- No license chosen -- you must choose a license, e.g.:
+ isempty(license) && error("""
+  No license chosen -- you must choose a license, e.g.:
 
- julia> Pkg.scaffold("$pkg", license="MIT")
- """)
+  julia> Pkg.scaffold("$pkg", license="MIT")
+  """)
  haskey(LICENSES,license) ||
  error("$license is not a known license choice.")
- avail = Dir.cd(Read.available)
- haskey(avail,pkg) &&
- error("$pkg is already a registered package name.")
- d = Dir.path(pkg)
+ d = if isempty(dir)
+ avail = Dir.cd(Read.available)
+ haskey(avail,pkg) &&
+ error("$pkg is already a registered package name.")
+ Dir.path(pkg)
+ else
+ joinpath(dir,pkg)
+ end
  ispath(d) &&
  error("$d exists, refusing to overwrite.")
  mkpath(d)