See:
- https://github.com/Homebrew/homebrew-core/issues/165388
- https://trac.macports.org/ticket/69639

This avoids interfering with the build-matlab directory that may already be
used by the developper locally. Also, this makes it symmetric with the Windows
build script.

The binary location had not been updated following the move of the dseries
submodule (commit e962cb4d).

Incidentally, this means that the JSONlab submodule is no longer needed, so it
is removed in the present commit.

Closes: #1907

Ref. #1907

[skip ci]

[skip ci]

Added double quotes to variables

id="org.dynare.VERSION_NO_SPACE" fixes #1790, i.e old Dynare versions will not get uninstalled.

because MATLAB checks the directory of Xcode and not of the Command Line Tools

Fixes #1893
Closes #1894
Explain how to get Xcode CLT and gcc via homebrew in installer at the end using a conclusion.html file.
Clarify this also in the manual.

By the way, simplify the dependency build system by removing 32-bit
SLICOT (was only used for the Octave package), and the symlinks for MatIO and
GSL (no longer needed with Meson).

[skip ci]

The formulas are taken from commit 46401325ed2c4d72adb6f1592cf6096bb844b489 of
the homebrew-core repository.

The gcc.rb formula was modified by adding “cellar: :any” to all bottles (see
https://github.com/Homebrew/brew/blob/master/docs/Bottles.md).

The preprocessor has been updated accordingly.