v0.5.5

compiled on Ubuntu 14.04.2 LTS, x86_64

new features:

1. add last & last_raw interfaces

bug fix:

1. fix bug of query.merge

// CHANGE LOGS
// 0.4.8 fix filename bug emporarily, fix dirty-index-cache bug of query,
// add filter for debug
// 0.4.9 mv db back to g, add rpc.last
// 0.5.0 rm trace, add history&last api
// 0.5.1 add http interface v2, using form args
// 0.5.2 add last_raw
// 0.5.3 fix bug of last&last_raw
// 0.5.4 fix bug of Query.merge
// 0.5.5 use commom(rm model), fix sync disk