load path

[StefanKarpinski]

Currently we have a half-baked, implicit load path for .j files loaded via the builtin load() function. It should be possible to add a list of directories to look in for .j files. The rule should probably be that names without / in them are looked up via the load path, while names beginning with / are considered to be absolute and names with / anywhere else are relative to the current directory.

[JeffBezanson]

Can be done as part of the redesign discussed in issue #65.

[StefanKarpinski]

Yeah, I can start looking at how to do these two together. Would be a big combined win.

[JeffBezanson]

This is already in util.j, but there is no user interface to it. What should it be?

[StefanKarpinski]

Ah, ok. This is pretty easy now. I think should just have

const LOAD_PATH = String["", "$JULIA_HOME/", "$JULIA_HOME/j/"]

and always use that to look for files that get loaded. People can just manipulate the contents of that array like any other array. It's pretty straightforward. Does seem reasonable to you?