Fix error wording

Use 'saltenv' instead of 'environment'
another error wording fix
correct error messages
Add error message when git CLI is not present and gitfs is enabled

We can't be sure that package dependencies will ensure it is installed.
Merge pull request #11583 from s0undt3ch/2014.1

2014.1 tests configuration handling cherry-picks
Merge pull request #11563 from terminalmage/error-wording-tweaks-2014.1

Tweak error wording
Merge pull request #11566 from terminalmage/gitpython-nogit-error

Add error message when git CLI is not present and gitfs is enabled
Call `super()` instead.

Why wasn't super being called?