examples/juniper various improvements (issue #236 plus more):

[attila123]

• Old, python 2 style print statements replaced with logging.info() (logging configured to show date, python file name and line number),
• Using bigger timeout values for manager.connect(), needed by e.g. Juniper SRX 300 (which I could test with) for some operations,
• More meaningful, less confusing/misleading/sloppy variable names,
• get-configuration-jnpr.py: fix: the result of get_configuration() used a bit different data structure,
• get-xnm-information.py: XML (NCElement) to str conversion fix for python 3,
• Some/most PEP 8 code formatting issues were fixed (what I noticed in PyCharm),
• Unnecessary user input (raw_input()) removed from the examples where it was present, easier to run them this way (especially multiple times),
• Note: some examples may still be broken, did not have time to debug all of them.

[coveralls]

Coverage decreased (-0.6%) to 68.41% when pulling a7ac610 on attila123:examples_juniper_various_improvements into 23df9a7 on ncclient:master.