TS-1739: Fix TODO within varFloatFromName()

Return value from RecGetRecordDataType() should be checked, and
fix harmless but weird conversion type.

Signed-off-by: Yunkai Zhang <qiushu.zyk@taobao.com>
Signed-off-by: Zhao Yongming <ming.zym@gmail.com>
TS-1738 stats: missing "proxy.cluster.cache_total_hits_mem" in RecordsConfig

1. we had defined "proxy.node.cache_total_hits_mem", a corresponding clsuter
   record should be defined.

2. "proxy.cluster.cache_total_hits_mem" are using in stats.config.xml file,
   missing definition will cause unexpected result.

BTW: fix weird tailling spaces by my VIM automatically.

Signed-off-by: Yunkai Zhang <qiushu.zyk@taobao.com>
Signed-off-by: Zhao Yongming <ming.zym@gmail.com>