Improve OBJECT HELP descriptions.
Improve OBJECT HELP descriptions.

See #4472.

PKRoma/redis,GitHubMota/redis,soveran/redis,yossigo/redis,soveran/redis,soloestoy/redis,charsyam/redis,antirez/redis,charsyam/redis,neomantra/redis,Sciumo/redis,GitHubMota/redis,antirez/redis,pmem/redis,ctripcorp/redis,PKRoma/redis,nnog/redis,nnog/redis,spinlock/redis,pmem/redis,neomantra/redis,ofirluzon/redis,rogerchina/redis,ofirluzon/redis,Sciumo/redis,rogerchina/redis,soloestoy/redis,charsyam/redis,antirez/redis,charsyam/redis,ofirluzon/redis,oranagra/redis,neomantra/redis,spinlock/redis,rogerchina/redis,yossigo/redis,soveran/redis,Sciumo/redis,oranagra/redis,Sciumo/redis,PKRoma/redis,GitHubMota/redis,pmem/redis,soloestoy/redis,PKRoma/redis,oranagra/redis,PKRoma/redis,ctripcorp/redis,rogerchina/redis,nnog/redis,charsyam/redis,soloestoy/redis,ctripcorp/redis,antirez/redis,nnog/redis,ctripcorp/redis,neomantra/redis,oranagra/redis,soveran/redis,yossigo/redis,GitHubMota/redis,ofirluzon/redis,soloestoy/redis,oranagra/redis,spinlock/redis,yossigo/redis,pmem/redis,neomantra/redis,spinlock/redis,ofirluzon/redis,yossigo/redis