Fieldmanager translations

[enrico-sorcinelli]

This PR aims to load translation files for the plugin and adds italian translations.

I don't see an existing thread for it, as well as this feature doesn't appears on 1.1 road map.

During translation I also fixed some very similar strings in order to reduce duplicated messages.

Moreover some enhancement to string messages should be done:

• Avoid to leave blank spaces at the end of messages:

For example in php/class-fieldmanager-group.php (line ~ 145)

esc_html( sprintf( __( 'Group child name conflict: %1$s / %2$s', 'fieldmanager' ), $name, $element->name ) );

could be better than:

esc_html__( 'Group child name conflict: ', 'fieldmanager' ) . $name . ' / ' . $element->name );

• Normalize the syntax used in the messages:

Sometimes the double quotes (") were used to wrap code strings or values and sometimes not.
Sometime the backquotes (`) was used to wrap code and sometimes not.

Once we decided which syntax to use, I can work on this too.

[dlh01]

Hey @enrico-sorcinelli,

I think this would be great to have in Fieldmanager, and I want to try to help get it in.

I've been thinking about how we might be able to break up the tasks involved into smaller pieces, particularly the enhancements to existing strings. I'm going to try to come up with a plan for that and will post it for your feedback as soon as I can.

[dlh01]

@enrico-sorcinelli,

My plan to try to "break up the tasks" of preparing FM for translations hasn't succeeded, but I would appreciate your feedback on #571.

I tried to fix the issues with strings that you noticed, along with problems flagged by PHPCS, deviations from core, missing translator comments, etc. I hope the changes there would make it easier to write translations like yours.

[mboynes]

This is currently blocked by #571, but I'd like to get it in in the 1.3.0 milestone.