Tatoeba update (May 9th, 2015)

# Plurals #
* Improved handling of plurals in the user interface for languages such as Russian and Belarusian.

# Statistics #
​* The "Sentences by language" page was updated graphically. It still contains the same information as before.
* There are 2 new statistics pages:
** The number of members in each language for each level. This page can be accessed from the menu: "Members" > "Languages of members". Previously, this link was redirecting to a specific language (the one with the highest number of members). Now we can have global statistics.
** The number of native speakers in each language for each user status. This page can be accessed from the menu: "Members" > "Native speakers". The user status icons should be improved to work for color blind people. Suggestions are welcome.

# Miscellaneous #
* Improved furigana for words that start with a kana character.
* Updated the list of donations. Thanks to those who have contributed.