fixed some mistakes and added in some new translations

Update minetest.po

Update minetest.po

ok @Zeno- @nerzhul

I am a native speaker. I have corrected all the mistakes I've found.

Update Spanish language

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

This reverts commit e4e4324a.

Conflicts:
	po/minetest.pot
	po/*/minetest.po

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

Errors found by @Sokomine.

Signed-off-by: Craig Robbins <kde.psych@gmail.com>

This reverts commit 4432e982.

Exception: "Nom / Mot de Passe" --> "Nom / Mot de passe"

Notes (in french) :

72 msgstr "Ok" : OK est un acronyme, pas un nom, donc majuscules.
193 msgstr "Feuilles transparentes" : quel type de feuilles ? Trop vague.
213 msgstr "Filtrage anisotropique" : oxymore.
229 msgstr "Précharger les visuels d'objets" : doit être écourté (dépasse trop la bordure grisée)

wrong expression and wrong word order