Fix Python 3 Syntax Errors (en masse)

[cclauss]

Like the other en masse PRs, #3206 and #3220 but this one focuses on fixing Python 3 syntax errors. Each line modified in this PR is one of the following:

• A Python 3 syntax error like old style print or old style exceptions or explicit tuples as function parameters, etc
• from __future__ import print_function # only used where needed
• from six.moves import xrange # should have been in from six.moves import xrange (en masse) #3206 but was hidden by a syntax error
• from six.moves import input
• raw_input() --> input()
• TabError
• explicit tuples as function parameters
• trailing whitespace at end of line or end of file (my editor chews these up on save)

@nealwu

[tensorflow-jenkins]

Can one of the admins verify this patch?

[nealwu]

Thanks for sending this! Two comments below.

[nealwu]

This needs from __future__ import print_function above.

[cclauss]

Thanks! Done.

[nealwu]

Same here--we need from __future__ import print_function.

[cclauss]

Thanks! Done.

[nealwu]

Excellent!