* hunspell: write autoreconf method to triage error
This commit fixes the error described in GitHub issue
`AutotoolsPackage` class attempts to call `libtoolize`, which doesn't
exist on macOS systems that externally install `libtool` in Spack via
Homebrew -- Homebrew installzes GNU libtoolize as `glibtoolize`.
The fix is to call `autoreconf` only, and GitHub pull request #12344
makes this change in
AutotoolsPackage (https://github.com/spack/spack/pull/12344). However,
while waiting for that pull request to be merged, overriding the
`autoreconf` method achieves the same result for a self-contained
fix. This self-contained fix is necessary to fix a dependency bug in
the `hunspell` package.
* hunspell: add missing gettext dependency
* hunspell: add version 1.7.0
- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
