Added support for functional parameter (#33)

[pawlizio]

This fixes tilt support for exterior blinds

[coveralls]

Coverage decreased (-0.7%) to 81.631% when pulling 97bb054 on pawlizio:master into b685774 on Julius2342:master.

[Julius2342]

Hi @pawlizio !

there is a merge conflict now in your branch. May i kindly ask you to fix this?

I also dont understand your patch, may you write one or two sentences about your change?

Thank you very much!

Best

Julius

[pawlizio]

Dear @Julius2342,

pyvlx has no support to set the functional parameter of a node (see Chapter 10.1.1.4 to 10.1.1.6 and 14 Appendix 2 of Technical Specification for KLF 200 ). On my exterior venetian blinds it is possible to set the tilt of the slats with functional parameter 3.

I moved from tahoma premium box to velux klf in order to be independent from the internet access. With somfy component I was able to set the tilt of my raffstores with home assistant, so I tried to get it also working with velux. Finally it took me some time to understand your code as well as the velux api specification, but luckily I managed to get it working.

I'll try to identify the issue, however I'm not an experienced developer, so it may will take some time to understand where the conflict is.

Best regards,
Paul

[pawlizio]

@Julius2342 I have now resolved the conflict and added more comments to explain my code.

[Julius2342]

sigh i broke it again. This time i will fix it ...

[Julius2342]

I fixed the conflict in MR #39 May you have a look please?

[pawlizio]

#39 has a problem, as the Blind constructor in node_helper.py get an unexpected keyword argument 'position_parameter'

[Julius2342]

Thank you :)