Adds get_new_ids and at_addrs functions

[spacether]

In conducting a memory leak investigation, I found it helpful to look at my new objects created between calls to show_growth. So I made two new functions to help users out here.

get_new_ids is like show_growth, except that it stores dictionaries which hold sets of object address ids. So now one can grab a set of all the new 'list' ids.

at_addrs: Once one has the new 'list' ids, one can call at_addrs to go from a set of ids to the objects at those addresses. One can then make graphs of the back references on those new objects.

[spacether]

@mgedmin

• I reverted my changes so there are now no new generated images in the docs folder
• Version number is fixed
• Function name is changed from get_ids to get_new_ids
• Object ids are now stored in a _state argument in get_new_ids
• Working tests added to the docstrings of get_new_ids and at_addrs

Any other updates?

[spacether]

@mgedmin Any other updates?

[spacether]

@mgedmin

• Key deletion has been moved outside of the iteration loop
• limit = None or >= 0 may now be passed in to get_new_ids

[spacether]

@mgedmin I made the updates that you suggested. Can you merge them in and post the new version on pypi?

[mgedmin]

Thank you!

[mgedmin]

objgraph 3.4.0 is out on PyPI.

[spacether]

Thanks!