Update ejs.js

Able to identify and remove BOM header.

new function:
line = 52

/**
 * Render an EJS file at the given `path` (easton changed)
 * @param {String} path
 * @param {String} encoding
 * @api private
*/
function readEJSFile(path, encoding) {
    var buffer = read(path);
    if (buffer[0] == 239 && buffer[1] == 187 && buffer[2] == 191) {
        buffer = buffer.slice(3);
    }
    return buffer.toString(encoding);
}