The shell script configure was assuming the existence of option
-camldir which was removed in 333d41a9.

  configure is now just a minimal wrapper around the new configure.ml.
  This configure.ml is runned with the same ocaml used during
  compilation, and starts with a #load "unix.cma".
  For now, this new configure script is meant to be 99% compatible
  with the old one. Known incompatibilities : the --foo option format
  (with two --) isn't supported anymore, use -foo options instead.
  Let me know if you encounter any other changes.

  Internals:
   - We use our own "run" command (based on Unix.create_process) to avoid
     relying on some specific shell (/bin/sh or cmd.exe).
   - We should have far less issues with filename quoting under windows
     since we almost never rely on (cygwin) shell anymore. This remains
     to be fully tested, though.
   - dev/ocamldebug-coq is slightly different now, to ease its generation

Attempt to adapt .el files too.
doc/refman/RefMan-uti.tex has still to be fixed.

 Let's avoid the "if a=$(cmd ...)" since:
 - unless being a shell expert, it's not obvious it's testing the exit code
   of cmd.
 - it's quite fragile, if you pipe cmd into a cmd2 you'll lose the
   exit code of cmd.

 Instead, we test the emptiness of the variable content afterwards

 Keeping the earlier content of this variable is crucial for opam
 (at least).

 Thanks to François Bobot and Thomas Refis for this one...

 - after piping with | tr -d, an exit code was lost
 - suspicious use of " " inside a larger " ", we use ' ' now instead

Also add a 2 in an error message (it's gSourceView2, not gSourceView).

This closes bugs 3150, 3151, 3152, and 3153.