consistent descriptions in readmes
add basic jetty and tomcat readmes with descriptions
add consistent Install sections to projects

remove install sections for templates since they aren't needed
consistent developer notes sections in readmes

Removed mention of lein sub install and lein version in other readmes since
they're covered in the top readme
consistent USAGE in readmes

* USAGE is only app-template and service-template
* Moved the app's USAGE to the generated app which is
more useful to the end user and consistent with service
add missing explanation of LATEST_VERSION
explain how to develop on templates per Ryan's suggestion
Merge pull request #208 from pedestal/consistent-subproject-readmes

Consistent subproject readmes