Fix i18n issues, add Italian language

This release fixes issues with how ngx-translate was being used with ManUp. ManUp now loads its translation strings just before it needs to present an alert. Previously, it loaded translation strings on initialisation. This could cause issues with the host app losing translation strings, or ManUp showing raw untranslated strings to the user when presenting an alert.

All detailed in #31

Italian Language Support

This release also adds translation support for Italian language! Thanks @grcasanova for the contribution!