Seamm-installer

* Working with the new packing lists, generated by installing SEAMM now that we
cannot programatically search PyPi.
* Added support for dependencies with pinned versions, which is becoming increasingly
necessary.
* Use conda env update with custom environment file which include any pinning
needed. This appears to avoid the problems with updating encountered with the last
version.

* Moved seamm.ini from ~/SEAMM to ~/seamm.d since it only contains personal preferences.

* Install and update now use the latest version unless the package is pinned in the
packing list.
* Changes to support the plug-ion specific installs, which are now handling the
specific <code>.ini files.

2024.3.11 Updating to work with new packing list.
* Versions of packages are now stored as strings and compared using semver, since
the older approach is being deprecated in Python.

2023.4.2 Bugfix: Updating full conda environment breaks pinning.
So removed that capability.