Merge branch 'develop'

Add multi-port support.
Merge branch 'develop'

Add more command line options, simplify code.
Merge branch 'develop'

Add README.
Merge branch 'develop'
Merge branch 'develop'. Added update password feature.
Merge branch 'develop'. Add feature: encryption table cache.
Merge branch 'develop'. Add feature: multi-server.
Merge branch 'develop'
Merge branch 'develop'
Merge branch 'release/0.5'
Merge branch 'release/0.6'
Disable cgo in Makefile.
Enhance Linux startup script.
Print startup error message to stderr.
Merge branch 'hotfix/init-script' into develop