provision 6.x-1.6

Changes since 6.x-1.5:

• fix usage for hostmaster-install
• #1146238 by mig5: Fixed The Reset password task for Drupal 5.x sites creates not working one-time login link.
• fix the help information for most provision-commands by removing the site name argument and switch to @aliases instead. add examples for most commands too.
• #1322208 by helmo - fix provision-restore help information and add an example
• #1336838: Added documentation for --makefile to provision-save, and fixed the style.