Fixes creation of default directories on install.

* Changes DirectoryConfigManager to create default directories
  after porting .cloudcafe folder.
* Changes build_engine_directories() to always set user and group
  owner for the engine directory, recursively, to the real_user
  on install. (POSIX only, does not affect Windows).
* Moved safe_create_dir and safe_chown to PlatformManager
* Fixed zome pep8 issues

Change-Id: Iaad520e15ba0bf32209b7432e57d7abee3eec518