Console labeler adapted for ipython notebook

Active learning through the console labeler (dedupe.consoleLabel) did
not work in ipython notebook mode because it used the standard input
which only works in console mode. Now it checks if it's inside an
ipython notebook, using raw_input when appropriate.
All displaying and inputing in consoleLabel changed to print and raw_input

Also there is a small fix: Now `random.randint` used in `uncertainPairs`
matches `numpy.random.randint` behavior used somewhere else. It was
sometimes given data indices out of range.
`sys` dependency removed from `dedupe.convenience.consoleLabel`
Merge pull request #308 from daniel-acuna/ipynb-labeler

Console labeler adapted for ipython notebook
use older style print statements