refactor the naming within plugin new generator

Having a method called `full?`, which checks on :full and :mountable
is very confusing. I renamed `full?` to `engine?` and created a `full?`
method that only checks the `:full` option
change spy of  after invoked controller action. because ruby-2.0.0 waned unused variables
Fixes for PR [#8267]
* Fix Migration#reversible by not using `transaction`.

* Adapt mysql adapter to updated api for remove_column

* Update test after aedcd683684d08eaf30623a4b48ce31a31426372
Fix syntax error in controller template
Fix spacing regression in scaffold generator
Merge pull request #8588 from marcandre/fix_reversible

Fix Migration#reversible by not using `transaction`.
Remove warning of intance variable not initialized
remove duplication from Rails::Application docs
Merge pull request #8593 from shime/master

another little documentation fix
Explicit options should have precedence over railsrc on the `rails new`
command

Closes #8545
we're not supporting SQLite 2
Merge pull request #8594 from amatsuda/rm_sqlite2

I don't think we're supporting SQLite 2
"warning: ambiguous first argument; put parentheses or even spaces"
Merge pull request #8595 from amatsuda/regex_warning

"warning: ambiguous first argument; put parentheses or even spaces"
Add rake default to description
Add rake test description
reminder to run bundle after setting up rails-dev-box
chmod -x from non-script files
Merge pull request #8601 from amatsuda/chmod_x

chmod -x from non-script files
fetch highlighter option only when needed