Updates/corrections

A few updates to the site:

• Improvements to the Spanish dictionary entries for several common verb forms such as tengo. (Unlike many dictionaries, the Español-Inglés site's dictionary actually treats some of these forms specially, and includes some common phrases with those declined forms as well as a redirection to the base form such as the infinitive.)
• Various other new words and phrases have also been added to the dictionary.
• A few additional entries in the list of Mexican Spanish words.
• Some additions to the page on Spanish pronunciation, in particular the description of the Spanish ñ sound.