修复cocos2dx的Label，WP8下不能换行的问题

FT_Error CCFreeTypeFont::addWord(const std::string& word) 
{
    std::vector<TGlyph> glyphs; // glyphs for the word
    FT_BBox             bbox;   // bounding box containing all of the glyphs in the word
    int maxWidth = m_inWidth ? m_inWidth : m_windowWidth;
    std::string newWord;

    if(m_currentLine->width > 0) 
    {
        newWord = ‘ ‘ + word;
    } 
    else
    {
        newWord = word;
    }

    FT_Error error = initWordGlyphs(glyphs, newWord, m_currentLine->pen);
    if(!error) 
    {
        compute_bbox(glyphs, &bbox);
        /*判断添加进去后整个line是否显示宽度大于设定宽度，是的话进行截取*/
        if (Application::getInstance()->getCurrentLanguage() == LanguageType::CHINESE && bbox.xMax > maxWidth)
        {
            std:size_t start = 0, end = word.length();
            while (true)
            {
                while (true)//这个字符比最宽还要宽，则进行截取
                {
                    end--;
                    FT_BBox validBBox = bbox;
                    std::vector<TGlyph> validGlyphs;
                    FTLineInfo validLine = FTLineInfo();
                    validLine.width = 0;
                    validLine.pen.x = 0;
                    validLine.pen.y = 0;
                    //对UTF8字符进行切割
                    if (end != word.length())
                    {
                        while (true)
                        {
                            unsigned char utf8charpart = word.at(end - 1);
                            if ((utf8charpart & 0x80) != 0 &&
                                (utf8charpart & 0xe0) != 0xc0 &&
                                (utf8charpart & 0xf0) != 0xe0 &&
                                (utf8charpart & 0xf8) != 0xf0)
                            {
                                end--;
                            }
                            else
                            {
                                end--;
                                break;
                            }
                        }
                    }
                    std::string validStr = word.substr(start, end - start);
                    FT_Error validError = initWordGlyphs(validGlyphs, validStr, validLine.pen);
                    if (validError) break;
                    compute_bbox(validGlyphs, &validBBox);
                    if (validBBox.xMax <= maxWidth)
                    {
                        m_currentLine->glyphs.insert(validLine.glyphs.end(), validGlyphs.begin(), validGlyphs.end());
                        if (m_currentLine->width == 0)
                        {
                            m_currentLine->bbox = validBBox;
                        }
                        else
                        {
                            m_currentLine->bbox.xMax = validBBox.xMax;
                        }
                        break;
                    }
                }
                start = end;
                end = word.length() + 1;
                if (start == end - 1) break;
                bbox = FT_BBox();
                endLine();
                newLine();
            }
        }
        else
        {
            if (m_currentLine->width == 0 || bbox.xMax <= maxWidth)
            {
                m_currentLine->glyphs.insert(m_currentLine->glyphs.end(), glyphs.begin(), glyphs.end());
                if (m_currentLine->width == 0)
                {
                    m_currentLine->bbox = bbox;
                }
                else
                {
                    m_currentLine->bbox.xMax = bbox.xMax;
                }
                m_currentLine->width = m_currentLine->bbox.xMax - m_currentLine->bbox.xMin;
            }
            else
            {
                endLine();
                newLine();
                addWord(word);
            }
        }
    }
    return error;
}