一个基于QR Code encoder的 php 扩展，更高效的生成二维码

<code>DCode::qrcode(<span>$string</span>, <span>$version</span> = <span>0</span>, <span>$level</span> = QR_ECLEVEL_L, <span>$mode</span> = QR_MODE_KANJI, <span>$casesensitive</span> = <span>0</span>);</code>

<code>DCode::qrcode8bit(<span>$string</span>, <span>$version</span> = <span>0</span>, <span>$level</span> = QR_ECLEVEL_L);</code>

<code>DCode::qrcodedata(<span>$size</span>, <span>$data</span>, <span>$version</span> = <span>0</span>, <span>$level</span> = QR_ECLEVEL_L);</code>