Add some localizations

• Danish (da) by @chripede
• Hebrew (he) by @udidoron

Events support

Events tbwfocus and tbwblur were added on element. Example:

$('#editor')
.trumbowyg()
.on('tbwfocus', function(){
    console.log('focus event fired');
})
.on('tbwblur', function(){
    console.log('blur event fired');
});

Thanks @temuri416 in #66 for proposal.

Improve direction option support in languages files

You can now specify direction of language directly in localizations files, with _dir like that:

jQuery.trumbowyg.langs.he = {
    _dir:           "rtl",

    viewHTML:       "צפה ב-HTML",