Install: <module>_installer::install() is called, any necessary tables
are created.
Activate: <module>_installer::activate() is called. Module
controllers are routable, helpers are accessible, etc. The module is
in use.
Deactivate: <module>_installer::deactivate() is called. Module code
is not accessible or routable. Module is *not* in use, but its tables
are still around.
Uninstall: <module>_installer::uninstall() is called. Module is
completely removed from the database.
Admin > Modules will install and activate modules, but will only
deactivate (will NOT uninstall modules).
core_installer::install() now takes an $initial_install param that
allows us to enforce that we're doing a clean install. Use this in
both the scaffolding and the unit test code.
Greatly simplify the scaffolding uninstall/reinstall code.
scaffolding and unit test code so that we can use it consistently.
This fixes an issue where adding a module was not refreshing the
statically cached module list causing the test framework to break.
