Update git version to 2.0.5.
Create a system git config at install.
Fix typos in git software definition.
Add git update to changelog
Move omnibus gitconfig from software definition to recipe and make configurable.
Use dashes and underscores correctly, add a section to gitlab.rb template.
Merge branch 'global_gitconfig_configurable' into 'master'

Global gitconfig configurable

Fixes #385

See merge request !270