Name conflict between hour and Planck's constant

[choloepus]

constants_en.txt defines "h" as Planck's constant, but default_en.txt defines "h" as hour. The result is that ureg.h ends up as the hour.

I would recommend removing "h" from default_en.txt, since "hr" and "hour" are pretty good names for the hour, but "planck_constant" is rather unwieldy and there is no other widely used abbreviation.

This line of default_en.txt is also used as an example in the documentation on the "Defining units" page, so it should be changed there as well if default_en.txt is changed.

[hgrecco]

Agreed. I will change this soon.