Until Ansible 2.9 it looks like ansible_become_password had higher priority.
From Ansible 2.10 ansible_become_pass has higher priority [1]. Mitogen was not
respecting this.
I may need to rework this further, instatiating the become plugin may have
slowed down execution.
[1] Based on testing with
```
[ubuntus]
become-pass-pass ansible_become_pass=1234
become-pass-password ansible_become_password=1234
become-pass-both ansible_become_password=wrong ansible_become_pass=1234
[ubuntus:vars]
ansible_host=ubuntu2004.local
ansible_user=ubuntu
```
```
- hosts: ubuntus
gather_facts: false
become: true
tasks:
- ping:
```
This refactors connection.py to pull the two huge dict-building
functions out into new transport_transport_config.PlayContextSpec and
MitogenViaSpec classes, leaving a lot more room to breath in both files
to figure out exactly how connection configuration should work.
The changes made in 1f21a30 / 3d58832 are updated or completely removed,
the original change was misguided, in a bid to fix connection delegation
taking variables from the wrong place when delegate_to was active.
The Python path no longer defaults to '/usr/bin/python', this does not
appear to be Ansible's normal behaviour. This has changed several times,
so it may have to change again, and it may cause breakage after release.
Connection delegation respects the c.DEFAULT_REMOTE_USER whereas the
previous version simply tried to fetch whatever was in the
'ansible_user' hostvar. Many more connection delegation variables closer
match vanilla's handling, but this still requires more work. Some of the
variables need access to the command line, and upstream are in the
process of changing all that stuff around.