[Model] section 3.2.5, 3.2.6 relationship with 4.7.6 and 4.8

Again readability issue.
Cross-referencing the two  sections 3.2.5 and 3.2.6 which are related to
more detailed section 4.7.6 and section 4.8, i think it would make sense
to have properties talked about first then events.

Events in section 4.7.6 refer to properties, so it would be useful to
detail properties first (ie swap section 4.7 and 4.8). 
And for consistency if properties are defined first in section 4, then
it is fitting to define them relatively first in section 3.2. 

cheers,
jamal