taa, 9-June-2011

Changes to support loading on Linux (64-bit, at least):
- Change maybe-defvar in loader.lisp to take an extra argument; we'll
  use that as a dir name if the first argument fails.
- Add "1" to *load-foreign-types*: /usr/lib64/libGL.so.1 is not
  otherwise recognized as a foreign file.
We still have to make a symlink from /usr/lib64/libGLU.so
  ->libGLU.so.1, because stupid Franz (see
  /usr/local/acl82.64/opengl/linux-1.3/opengl.cl) doesn't look for a
  version. Similarly for libXi and libXmu.
- Copy most of the code for initializing the path variables from
  loader to exe-loader, because that seems to be what works.
- Rename QRM-binary to QRM-windows. There are corresponding QRM-linux
  directories now.
- in envisioner/exe-maker.lisp, reference environment variable
  OUTPUT_DIR (exported in Makefile) rather than "QRM-binary/".
- in envisioner/zgraph.lisp, make zgraph-shortcut-commands conditional
  on not being on *nix. Also in explain.lisp.
- in envisioner/defsys.lisp, comment out "ratsimp" require. Doesn't
  appear to be needed for anything.
- in QRG/zgraph/v9/defsys.lsp, fix case of "lisp" for call to
  make-qrg-path.
- in QRG/zgraph/v9/export.lsp, add zgraph-pane. Probably unnecessary
  with zgraph.lisp and explain.lisp changes above.
- in QRG/code-library/lisp/runtime-utils/files.lsp,
  (cg:process-pending-events) is conditional on :common-graphics and
  :mswindows.
- Fix some other path names that are only in doc, for consistency.
- in QRG/code-library/lisp/common-data-structs/defsys.lsp, fix case of
  "lisp" in qrg:make-qrg-path.