uhd: Add python 3.5

[mf2k (Frank Schima)]

Please add a python35 variant to the uhd ports.

[michaelld (Michael Dickens)]

Looks like UHD isn't quite ready for Python 3.5 yet. Here's the error I get when I add a +python35 variant and select it:

:info:build [  6%] Generating /Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/build/docs/nocscript_functions.dox
:info:build cd /Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/build/lib && /opt/local/bin/python3.5 -B /Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/uhd-77cbd56a5d09b29720aa309a9c95765c01ec9c65/host/lib/rfnoc/nocscript/gen_basic_funcs.py /Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/build/docs/nocscript_functions.dox
:info:build /Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/uhd-77cbd56a5d09b29720aa309a9c95765c01ec9c65/host/lib/rfnoc/nocscript/gen_basic_funcs.py:391: FutureWarning: split() requires a non-empty pattern match.
:info:build   func_list_split = func_splitter_re.split(func_list_wo_comments)
:info:build Traceback (most recent call last):
:info:build   File "/Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/uhd-77cbd56a5d09b29720aa309a9c95765c01ec9c65/host/lib/rfnoc/nocscript/gen_basic_funcs.py", line 474, in <module>
:info:build     main()
:info:build   File "/Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/uhd-77cbd56a5d09b29720aa309a9c95765c01ec9c65/host/lib/rfnoc/nocscript/gen_basic_funcs.py", line 469, in main
:info:build     write_manual_file(outfile)
:info:build   File "/Development/local/10_12/var/macports/build/_Development_sources_MacPorts_ports_github_macports_science_uhd/uhd-devel/work/uhd-77cbd56a5d09b29720aa309a9c95765c01ec9c65/host/lib/rfnoc/nocscript/gen_basic_funcs.py", line 455, in write_manual_file
:info:build     if not func_list_tree.has_key(func['category']):
:info:build AttributeError: 'dict' object has no attribute 'has_key'
:info:build make[2]: *** [docs/nocscript_functions.dox] Error 1

[michaelld (Michael Dickens)]

In a53525e9/macports-ports:

uhd*: add experimental +python35 variant; addresses ticket #52902 .

[michaelld (Michael Dickens)]

I went ahead and committed this change as "experimental"; it might work for someone else. Worst case is another ticket is opened with this variant failing (as I found it does) & I'll push it upstream to get fixed (and/or have me try to fix it).