change Lisp source & compiled file names in github to lower case

[masinter]

Filenames for Interlisp files are mainly upper case.
@nbriggs: except for the ones that people started writing from XCL, where they tended to use lowercase.

Unix and Windows default to lower case.

Or at least their users do.

I think Interlisp has a model where it will match either.

It's messier than you might think -- Unix file systems (outside of MacOS) are
usually case-sensitive. MacOS is case-insensitive and case-preserving (by
default), but you can mount file systems case-sensitive.

Ron has warned about some kind of whereis, filepackage problem, but
that could be solved by changing the files since case shift for ascii
characters in filenames doesn't change the lengths.

Second, we should have .tedit and .sketch as well as .interlisp or
.il .lisp (save for common lisp) .ilisp .medley are all possibilities.
With filetypes that know about medley.

Isn't there a bunch of code that knows that Interlisp source files don't have an
extension?

I don't think there's a bunch.

[masinter]

I'm not sure about using ".il" as an Interlisp source extension -- it's used for other things, and in particular, for maiko we already have files checked in with that extension -- it's what the Sun C compilers use for inline assembler code (e.g., dspSPARC.il and dsp386.il)

Originally posted by @nbriggs in #49 (comment)

.ilisp would be fine with me. .ilsp would be more Interlispy. .lisp should be used for Common Lisp.
.il isn't used all that often and would be better than nothing. .interlisp is too long.

Originally posted by @masinter in #49 (comment)

OK. I presume that when the filesystem file is foo.ilsp the file commands variable will be FOOCOMS? Still uppercase?

Originally posted by @nbriggs in #49 (comment)

Currently, the function FILECOMS, which should be the canonical way of mapping from a filename to its commands, packs on “COMS” to the NAMEFIELD of the file. So FOO.ILISP gives you FOOCOMS, foo.ilisp gives you fooCOMS.

Do we want to allow upper and lower case versions of the same file, with different commands? I think not.

Originally posted by @rmkaplan in #49 (comment)