Some newer *.py files are missing the `from __future__` boilerplate
that helps assure Python2 and Python3 compatibility.

allows passing flags like --pdb to test files
also add call to files where its missing

The `getargspec` needed to import the disassembler to support parsing
tuple arguments. Since numpy never uses those, the corresponding code
is deleted and an TypeError raised if such arguments are encountered.

Also fix the unused formatargs function so it does not require the
string module.

Run the 2to3 ws_comma fixer on *.py files. Some lines are now too long
and will need to be broken at some point. OTOH, some lines were already
too long and need to be broken at some point. Now seems as good a time
as any to do this with open PRs at a minimum.

The unicode fixer strips the u from u'hi' and converts the unicode type
to str. The first won't work for Python 2 and instead we replace the u
prefix with the sixu function borrowed from the six compatibility
package. That function calls the unicode constructor with the
'unicode_escape' encoder so that the many tests using escaped unicode
characters like u'\u0900' will be handled correctly. That makes the
sixu function a bit different from the asunicode function currently in
numpy.compat and also provides a target that can be converted back to
the u prefix when support for Python 3.2 is dropped. Python 3.3
reintroduced the u prefix for compatibility.

The unicode fixer also replaces 'unicode' with 'str' as 'unicode' is no
longer a builtin in Python 3. For code compatibility, 'unicode' is
defined either as 'str' or 'unicode' in numpy.compat so that checks like

    if isinstance(x, unicode):
        ...

will work properly for all python versions.

Closes #3089.

Python 3 removes the builtin types from the types module. The types
fixer replaces such references with the builtin types where possible
and also takes care of some special cases:

    types.TypeNone           <- type(None)
    types.NotImplementedType <- type(NotImplemented)
    types.EllipsisType       <- type(Ellipsis)

The only two tricky substitutions are

    types.StringType         <- bytes
    types.LongType           <- int

These are fixed up to support both Python 3 and Python 2 code by
importing the long and bytes types from numpy.compat.

Closes #3240.

The basestring class is not defined in Python 3 and the fixer replaces
it with str. In order to have a common code base we define basestring in
numpy/compat/py3k.py to be str when the Python version is >= 3,
otherwise basestring and import it where needed.  That works for most
cases, but there are a few files where the version dependent define
needs to be in the file.

Closes #3042.