Bug 1263 - Add .gitignore to md-sal-app-simple archetype

* Modified the generate project so that you need to run generate
from the specific generate directory.
* Added a .gitignore file which ignores the generate directory,
along with some other standards that we generally want to ignore.

Change-Id: Icb750b5383d391a364e0d0b8a7b46802394cfc33
Signed-off-by: Devin Avery <devin.avery@brocade.com>