return users when search user keyword is empty

fix for spring security auth table case issue

fix potential conditional npe

support spring security auth

Add ConditionalOnProfile and ConditionalOnMissingProfile annotations

Config service cache and namespace name normalization

1. Enable config cache to improve config service performance, just set
config-service.cache.enabled to true in ServerConfig
2. Normalize the namespace name in case the one provided has character
case issue

output ClassLoaderUtil exception to logger

Update CatEventType to TracerEventType

0.9.0-SNAPSHOT

use emptyList instead of creating a new list every time.

startup script check whether pid is alive

add build.bat and add notice on meta servers

Misc change

add comment why PropertySourcesProcessor implements BeanFactoryPostProcessor instead of BeanDefinitionRegistryPostProcessor

Cat单词不应出现在方法名，此处简化去除一下

实际方法名由Apollo官方决定。