many improvements

data/config/pamac.conf

examples/python/appstream.py

examples/python/test-infos.py

po/POTFILES

po/pamac.pot

resources/transaction_sum_dialog.ui

src/alpm_config.vala

src/alpm_utils.vala

src/cli.vala

src/database.vala

src/installer.vala

src/manager_window.vala

src/pamac_config.vala

src/system_daemon.vala

src/transaction-cli.vala

src/transaction-gtk.vala

src/transaction.vala

src/transaction_interface.vala

src/transaction_interface_daemon.vala

src/transaction_interface_root.vala