All supported hooks (so far) are:

  init
  pre_install
  post_install
  pre_uninstall
  post_uninstall
  pre_build
  post_build
  exit

Three example plugins added:

* post_install/wings3d/00_install_missing_deps.sh
   - installs needed deps that PPM/Pkg don't pick up by default

* post_install/gimp/50_install_plugins.sh
   - only runs if `--ask` was given, asks to install gimp plugins

* post_install/00_fix_deb_packages.sh
   - runs only when a `.deb` package is installed.. does nothing, just an example