ColourGradient::createLookupTable (and probably others)

[edit] I’m not sure what is going on here so I’m editing this until I have a better fix on it:

On my install of Mandriva the _hypot function used in

is not defined.

mathinline.h defines hypot, and some headers seem to suggest that _hypot should be aliased to hypot, but I haven’t yet managed to follow the linking order to find out if they are ever used or obsolete. Either way, a brute force alias of _hypot to hypot got me out of trouble.

This is really annoying - seems like the mac, windows and different versions of linux all use either hypot or_hypot, but it’s pretty much random whether they include the underscore. (What the hell’s the point of having an underscore anyway???)

I might add a juce_hypot function so at least there’s only one place it’d need to be changed.