Updated to param 2.0 API

[philippjfr]

Methods updated:

• debug
• defaults
• force_new_dynamic_value
• get_param_values
• get_value_generator
• inspect_value
• message
• params
• pprint
• print_param_defaults
• print_param_values
• script_repr
• set_default
• set_dynamic_time_fn
• set_param
• state_pop
• state_push
• verbose
• warning

[philippjfr]

I've changed all the methods that I think should definitely be moved onto the param subobject, leaving only get_param_values, params and pprint which I think are the most useful methods. We should decide whether we want to simply move everything or if we want to leave these commonly useful methods or do something else entirely, e.g. by moving and renaming them.

[jbednar]

My vote is for obj.get_param_values() to become obj.param.values() and for obj.params() to become obj.param.objects() (or something similar). I would't mind having obj.pprint() stay where it is, but it's not something I almost ever use, so I'd vote to move it to obj.param.pprint() for consistency. Note that these are all changes on Param, rather than HoloViews, which would need to happen before reflecting such changes here.

[jlstevens]

I quite like obj.param.values() but I'm not sure about obj.param.objects().

[jbednar]

Got anything better? :-) "values" is obvious; what to call the Parameter objects is much less obvious, because their name is "Parameter" but we have to distinguish it from the value, and "parameter" can mean "value"....

[jlstevens]

The Parameters object could be callable. So you could use obj.param('x') to get the 'x' parameter...

[jbednar]

obj.param('x') is fine, though obj.param.x is a lot more readable. But regardless, obj.param.objects() (or something like it, e.g. obj.param.definitions()) is still needed.

[jlstevens]

I'm going to go ahead and merge. I think it is important we make this change and test it as it is now - the remaining changes can go into a subsequent PR.