Spanish translation

[dani-sanchez-dorado]

Good Redmine Plugin!

I have integrated it in my redmine system, and I have created the spanish translation. Here you have my little contribution to the project:

`

# Spanish strings go here for Rails i18n
es:
supported_languages: Lenguajes soportados en esta versión
highlighting_theme: Esquema de colores usado
try_it_link: "Prueba este tema con una demo online:"
code_theme: Esquema de colores
code_theme_title: Cambiar el esquema de colores
allow_redefine: Permitir cambios de esquema de colores por usuario

`

Thanks!