Remove deprecated constructor for HdrDecoder

[RunDevelopment]

I removed the deprecated and internally unused new_nonstrict constructor for HdrDecoder.

This is the last deprecated item in image.

[fintelia]

This method was only deprecated 3 weeks ago, and the deprecation note points at a method that isn't public. I think this might need a bit more attention first...

[RunDevelopment]

Good catch! I didn't check when it was deprecated.

I think just explaining things a bit more in the docs of new and with_strictness should clear things up.

Also, should with_strictness be renamed to new_with_strictness? Sounds more like a constructor.

[197g]

Since Rust has no special 'constructor', new_ as part of names is superfluous. If you look at the standard library then from_ and with_ are both heavily used (with the former preferred where the latter could mistaken for a builder pattern).

[RunDevelopment]

Special or not, what's a constructor if not a static factory method? I just like to call them that here, since that's what their role is.

But after looking at BufReader::with_capacity, I think with_strictness should be okay.