Future stage1 python3

This is on the top of the previous travis PR. This converts some code to python 3 syntax (which works on python 2 with `__future__`), mostly this is print statements.

Python 3 is still not running, so I think next up ought to be imports (absolute don't seem to work in [stage1](http://python-future.org/automatic_conversion.html#stage-1-safe-fixes) which is weird ?) [see 3.4 build](https://travis-ci.org/hayd/pattern/jobs/39313097) then comes the actual hard work: string / btyes (probably this needs six)...

Note the warning from the future --stage1:
```
RefactoringTool: Warnings/messages while refactoring:
RefactoringTool: ### In file examples/05-vector/07-slp.py ###
RefactoringTool: Line 101: Calls to builtin next() possibly shadowed by global binding
RefactoringTool: ### In file pattern/server/cherrypy/cherrypy/_cpcompat.py ###
RefactoringTool: Line 324: Calls to builtin next() possibly shadowed by global binding
RefactoringTool: ### In file pattern/server/cherrypy/cherrypy/_cpcompat.py ###
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
RefactoringTool: Line 165: could not convert: from urllib2 import parse_http_list, parse_keqv_list
RefactoringTool: All module elements are invalid
```
*I tried running stage 2 but tbh it was a mess.*

Have a new error on `test_crawler_delay` not sure what it should be (https://travis-ci.org/hayd/pattern/jobs/39313093), again I think this needs looking at from someone who knows the codebase!