Create eo.js

Standard Esperanto keyboard layout (as /usr/share/X11/xkb/symbols/epo for example on Ubuntu) using 10-key-wide variant (ĵ under p) as found eg on official vanilla Android Esperanto layout.  Renders like http://lingvo.org/klavaro/firefoxos.png

The lists of alternate characters are chosen from  CEN WORKSHOP AGREEMENT CWA 13873:2000 (Multilingual European Subsets in ISO/IEC 10646-1) level MES-1 namely àáâãäåæçèéêëìíîïðñòóôõöøßùúûüýþÿāăąćĉċčďđēėęěĝğġģĥħĩīįıĳĵķĸĺļľŀłńņňŉŋōőœŕŗřśŝşšșţťŧțũūŭůűųŵŷźżž, together with characters such as δφγλωπψσθξ from the GSM 03.38 seven bit default alphabet, plus two more letters I noticed already added in the FirefoxOS keyboards ɛ ɵ which I added to avoid regression, and added a few currency symbols.   And noting that no alternate list should be longer than 10 characters.  Ordering is by Unicode number, with the exception of ß so that uppercase S and lowercase s are consistent, and currency symbols are placed last.

Written for https://bugzilla.mozilla.org/show_bug.cgi?id=940041
This line should be removed, or we cannot build Gaia to include this keyboard layout.
We could add the dictionary file later in another bug when we have the word list.