Partially migrated to print-function-like syntax

  For now we only handle the 'print' statement with a single argument,
  i. e.:

      print ... -> print(...)

  Migration was performed using a 2to3 fixer class:

      from lib2to3 import fixer_base, patcomp
      from lib2to3.fixer_util import Name, Call

      parend_expr = patcomp.compile_pattern(
          """atom< '(' [atom|term|testlist_gexp|STRING|NAME] ')' >""")

      class FixSinglePrint(fixer_base.BaseFix):
          PATTERN = "print_stmt"
          BM_compatible = True

          def transform(self, node, results):
              assert results
              assert node.children[0] == Name(u"print")
              args = node.children[1:]
              if len(args) != 1 or parend_expr.match(args[0]):
                  # We only fix 'print' statements which have _exactly_ one
                  # non-parenthesized argument.
                  return

              l_args = [arg.clone() for arg in args]
              l_args[0].prefix = u""
              n_stmt = Call(Name(u"print"), l_args)
              n_stmt.prefix = node.prefix
              return n_stmt
Finally fix DSSP problem.
Thank Lenna and Sergei for next release
Use built in next() function in test_NCBIXML.py

This change is enough to run this test file unmodified
under Python 3 where iterators don't have a next method
(see the new __next__ method instead). The next function
is built in in Python 2.6 onwards

We probably need to do this elsewhere in Biopython, this
particular test file is an interesting one to start with
because running 2to3 on it takes a long time.
Python 3 ready print statement/function
Can assume BytesIO available
This was breaking on Jython 2.7a2 (Mac)
Use built in next() function in misc test_*.py

Under Python 3 need to use next(iterator) rather than
iterator.next(), and this built in function is new in
Python 2.6 (so we couldn't use it until we dropped
support for Python 2.5).
Report slow files for 2to3
Phylo.draw_graphviz: deal with API breakage in networkx-1.8 (Issue #233)
Remove Python 2.5 hack for cmath.rect
Remove Python 2.5 specific hack in Seq method tests
Eric has contributed to the forthcoming release
Remove some really old FAQ entries in the Tutorial
More usage of iterator.next() in tests that I missed...

Now using built-in function next(...) in place of next method.
Remove commented out print statements
Resolve more print statements in the unit tests.
Fixed some old-style exceptions

These had been missed as they're split over multiple lines.
Fix line endings on test_ColorSpiral.py
Fix exception class typo