I have files for library classes that I need to use in multiple projects. I -could- put them in the library folder, but alas, then I can't edit them. (with the IDE)
A class does not qualify as a library, in my opinion, until it IS used in more than one project. When it is used in more than one project, it is a library, and should have already been debugged. So, editing should not be necessary.
Any text editor can be used to edit the library class files outside of the IDE. Save any edited files, then go to the IDE and compile and link the sketch. The library will be recompiled, too.
How about setting up the IDE so it can use aliases to my library files in my project folders? Would this be a doable change to the IDE? (Cause it can't do it now.)
If you are using a Unix variation, you can create symbolic links in the sketch folder to files that live elsewhere. If you are using Windows, you can create reparse points that serve the same purpose, programatically. I have no idea how you would do this using the Windows OS itself.