Support inspection

[bollwyvl]

the ? EOL magic and it's friends %p* are silly useful. The %p stuff breaks for other reasons (#12), while ? conflicts with the hy booleanizer:

print?

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-3-205c049c2135> in <module>()
----> 1 is_print

NameError: name 'is_print' is not defined

In addition to solving the typographic issue, would likely need to implement do_inspect to make macros inspectable as well.