reworked "createhome" (variable, passwd entry & issue #164)

[jasonvoor]

a few smaller changes:

• since createhome was referenced often, I changed it to be a variable
• even if createhome is false, it should create a passwd-entry with the home set
• fix for #164

[aboe76]

@jasonvoor thanks for your work, @javierbertoli thanks for reviewing.