removed obsolete deploy class
removed obsolete getOrderDetails method
use of params variable instead of $_POST

Also:
- fixed some coding typos
- reindented some ternary conditions to enhance readability (though IMHO
  ternaries should be replaced respectively by 'if' blocks)
changed displayJson by formatJson

By not echoing the results by default, we can choose what we want to do
with the results (and it's now testable)