Highlight messages and add newlines.
Use abort to exit script.
Add indentation back. Fix syntatical error.
Change vague name for variable 'a'.

'a' is such a silly name for a string that represents a command...
Merge distinguish-run-safe-message (#85) into master

Distinguish run_safe messages on error.

Adding newlines and highlighting the error will allow users to more
easily notice that their feature or hotfix command has failed.