Reduce unhelpful information shown by pinfo

[takluyver]

I've noticed recently that object introspection often shows information that's not very helpful, pushing the docstring and signature further down. In particular, 'Base Class' is redundant with 'Type' except for instances of old style classes, and 'Namespace: Interactive' is almost always the case. This clears those things up when appropriate.

I'm intending this for 0.14 now, but it's small enough that it could go into 0.13 if we want it.

Before:

In [2]: random.randint?
Type:       instancemethod
Base Class: <type 'instancemethod'>
String Form:<bound method Random.randint of <random.Random object at 0x95f38f4>>
Namespace:  Interactive
File:       /usr/lib/python2.7/random.py
Definition: random.randint(self, a, b)
Docstring:
Return random integer in range [a, b], including both end points.

After:

In [2]: random.randint?
Type:       instancemethod
String Form:<bound method Random.randint of <random.Random object at 0x84da8f4>>
File:       /usr/lib/python2.7/random.py
Definition: random.randint(self, a, b)
Docstring:
Return random integer in range [a, b], including both end points.

[takluyver]

Test results for commit 4e7dbac merged into master
Platform: linux2

• python2.7: Failed, log at https://gist.github.com/2984764 (libraries not available: oct2py rpy2)
• python3.1: OK (libraries not available: cython matplotlib numpy oct2py pymongo qt rpy2 wx wx.aui zmq)
• python3.2: OK (libraries not available: cython oct2py pymongo rpy2 wx wx.aui)

Not available for testing: python2.6

[fperez]

Test results for commit 4e7dbac merged into master
Platform: linux2

• python2.7: OK
• python3.2: OK (libraries not available: cython matplotlib oct2py pygments pymongo rpy2 wx wx.aui)

Not available for testing: python2.6, python3.1

[fperez]

I'm OK with this going in, it indeed removes mostly useless/redundant info. Code reviewed, looks good. Merging now. Thanks!