Make plugin translation ready about glotpress

[ocean90]

The PR just adds the text domain and the load_plugin_textdomain() call. That's fine.

But there are some other issues:

• Placeholders aren't explained in a translators comment
• The use of _n() is wrong in some cases, like _n('One translation rejected.', '%d translations rejected.', $ok, 'glotpress' ), $ok );
• Strings like __( 'edit', 'glotpress' ) should get a context: _x( 'edit', 'glossary', 'glotpress' )
• esc_attr( __( ) ) => esc_attr__( )
• echo _x( ) => _ex( )

How do we want to handle these? Move them into new issues?

[toolstack]

I'd vote for handling them as separate issues, they're all valid but shouldn't be a show stopper for 1.0 (maybe with the exception of _n()) , just something we can work on from release to release.

[polevaultweb]

+1 for a new 'enhancement' issue for after 1.0