Added GetGlyphRangesChineseSimplifiedCommon() helper that returns a list of ~2500 most common Simplified Chinese characters. Renamed GetGlyphRangesChinese() to GetGlyphRangesChineseFull() to distinguish other variants and discourage using the full set. (#1859)

Changed the accumulative encoding to remove the implicit +1 which only saved a little space and made things more confusing.