DB inspection

Added a few keywords to do easy familiar DB inspection with EdenTest
From the web2py book:

Beware! Given from gluon import current, it is correct to use current.request and any of the other thread local objects but one should never assign them to global variables in the module, such as in

request = current.request # WRONG! DANGER!

nor should one use current to assign class attributes:

class MyClass:
    request = current.request # WRONG! DANGER!

This is because the thread local object must be extracted at runtime. Global variables instead are defined only once when the model is imported for the first time.