[feature request] more pouch CMDs are required

[Letty5411]

Issue Description

Describe what happened:
As title, more pouch CMDs are required.

• pouch attach
• pouch attachkvm
• pouch build
• pouch commit
• pouch cp
• pouch diff
• pouch events
• pouch export
• pouch history
• pouch import
• pouch kill
• pouch load
• pouch login
• pouch port
• pouch push
• pouch restartkvm
• pouch save
• pouch search
• pouch stats: feature: add stats cli command #2640
• pouch tag
• pouch wait

Describe what you expected to happen:
Currently the following CMD has been supported:

• create
• exec
• gen-doc
• help
• image
• images
• info
• inspect
• login
• logout
• logs
• network
• pause
• ps
• pull
• remount-lxcfs
• rename
• restart
• rm
• rmi
• run
• start
• stop
• top
• unpause
• update
• upgrade
• version
• volume

How to reproduce it (as minimally and precisely as possible):
1.
2.
3.

Anything else we need to know?:

Environment:

• pouch version (use pouch version):
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others:

[allencloud]

I think this has been fixed most of the commands. Could you help to update the issue? @Letty5411 Thanks.

[chuanchang]

@allencloud Some commands like save and push are very common for users to manage container, could we implement them firstly?