* set preload_table correctly (fix #1524)
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* update res name in http module (fix #1544)
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* add bool convertor function
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* fix test fail
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* optimize update config method & add boolean conversion comments
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* remove comments
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* make cache_insert_data take effect in-service (fix #1521)
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* complete omitted config setter
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* cache_insert_data take effect for MemTable
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* add config test
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* rename config handler
Signed-off-by: NYhz <yinghao.zou@zilliz.com>

* #1240 Update license declaration of each files
Signed-off-by: Njinhai <hai.jin@zilliz.com>

* #1240 Update CHANGELOG
Signed-off-by: Njinhai <hai.jin@zilliz.com>

Former-commit-id: 898c2c8b0b2cfdc1b8664062aa0ea910a93566dd

Former-commit-id: 18ae9b5711cabd59baf7e0784583f99a655bf9c2

Former-commit-id: c817c67a409054a49da2be878872e885a0b3e041

Former-commit-id: aa281f8473100587c93afe7caf001ce640fbcc2d

Former-commit-id: e09b7dd7872372fa0ece9f5d18ec4c316b89cbe8

Former-commit-id: 69d1f1b661e6fc7779b4ae3abae60eeb28fa2b04

Former-commit-id: 33aeca704be0e7e80f1e45bb1dc11d1aafd4f4f3

Former-commit-id: 00da072153df8d103f6d232db6f945aff1bd2869