bash_env: Fix whitespace error

* There should be whitespace here and there isn't.  Some shells like it,
  some shells don't.  Be more correct by adding it.
bashrc: Clean-up env-set logic

* Move env-set options inside conditional that sources .bash_env.sh,
  this should almost always ensure that the functions are sourced
  prior to attempting to run them.
* Check that each variable is set prior to running env-set on it.  This
  ensures we don't set it to an empty string.