Xxh-xxh

**Features**
* In case of password authentication xxh will ask password once 31
* More ssh native behavior for password authentication

**Dev and test environment**
* `xde test` now have options to show failed command
* Short names for containers

**Code**
* First step to reduce sshpass dependency 30
* Global code reformat

**New features**
* Password auth with `+P password` and `+PP` options

**Fixes**
* `xonsh.AppImage` error about `which` fixed in https://github.com/niess/linuxdeploy-plugin-python/pull/19
* In AppImage extracted mode using more right way of running xonsh

**Code cleaning**
* Using path strings more naturally for xonsh scripts

**Dev and test environment**
* Added Arch Linux container with tests on password auth in [xxh-dev](https://github.com/xonssh/xxh-dev)

pip fixed

xpip` now works

Code cleaning

Faster getting host info