Source install now works. Paths now configurable. Added init.d.

Prior to this PR, source install is completely broken in nginx-formula.  This is a major patch that fixes it.

Additionally:
- Added many more optional pillar values to customize how nginx is compiled and where it is installed.
- Paths are now configurable. Kept same default values as before.
- nginx.conf template is now configurable.
- Upgraded default version to current stable release of nginx: 1.6.2
- Fixed ability to add custom modules (it did not work at all before)
- Removed explicit forced install of lua-nginx-module; if you want it, that should be added via the nginx:modules pillar like any other module
- Removed creation of directories that did not need to exist
- Added /etc/init.d/nginx that actually works
- Added optional ability to delete default config and html contents (you specify which files to delete in your pillar, if any)