Hi, I just upgraded to 4.7 but did a fresh install of the TinyMCE model (dropped old tinymce tables before installing new version of the module).
I first tried to get multiple language options for the spellcheck feature as described in:
http://tinymce.moxiecode.com/tinymce/docs/plugin_spellchecker.html
I tried adding to spellchecker/config.php the following versions of this line (which is what I understood from the link above):
$spellCheckerConfig[spellchecker_languages] = '+English=en,Espanol=es,';
$spellCheckerConfig[spellchecker_languages] = '+Espanol=es,English=en';
$spellCheckerConfig['spellchecker_languages'] = '+Espanol=es,English=en';
But none worked.
In any case, the main site is in Spanish, so I tried changing the default language to 'es':
$spellCheckerConfig['default.language'] = 'es';
Didn't work either.
I also went to admin/settings/tinymce and change the default language for the profile there to es, and no luck either.
I have not tried tinymce as a standalone feature, so I can't tell if the spellcheck plug-in for other-than-default-English is not (yet) supported in the Drupal tinymce module or if I'm doing something wrong or if it's a bug.
I did flush my cache (emptied cache table), disabled and enabled the tinymce module, looked for tinymce variables in the variable table and accessed the site from an alias domain just in case and to discard cache issues.