optimize TensorConstant constructor

Fix typo in function_dump doc

Check home_dir writing permission and assign temporary directory

fixed too-stringent typecheck in Rebroadcast.__init__()

New year 

DOC removed incorrect statement from compatibility docs

Added test for get_conv_output_shape method

Don't take the lock  unless needed at exit

Doc clarification and skip flake8 tests on auto saved file

[BUG] in python code and tests fix

Checks compiledir flag for prohibited characters. Fixes #3711

typo in bn.py documentation

Assorted Python 3 fixes

Add TypedListConstant, this fix an optimization warning.

Enable cudnn by default when avaialable in the new back-end

* use Python 2/3 compatible syntax for print;
* use range instead of xrange (creating a list of 100..1000 ints in Python 2 is not a big deal)