`inverselink()` inconsistent on master vs tagged versions for `LogitLink()`

[alanderos91]

On master the function returns the 3-tuple in the expected order. Looks like deriv and omμ are swapped on recently tagged versions, affecting releases:

• 1.9.3
• 1.9.2
• 1.9.1
• 1.9.0 <--- This is where I found the discrepancy.

It's almost harmless near μ = 0.5 but causes major headaches near the extremes.

On master:

GLM.inverselink(LogitLink(), -20.0)
# (2.0611536181902033e-9, 2.0611536139418488e-9, 0.9999999979388463)

On 1.9.2:

GLM.inverselink(LogitLink(), -20.0)
#(2.0611536181902033e-9, 0.9999999979388463, 2.0611536139418488e-9)

[andreasnoack]

See #586 and #588. I believe things are good on master, but the fixes were not backported to 1. Given that version 2 keeps being delayed, it might be good to backport those two fixes. I'll try that.

[andreasnoack]

I have opened #644