Export constants and aliases as well

Syncs list of exports with StatsFuns.

Author: devmotion

src/LogExpFunctions.jl

@@ -1,12 +1,13 @@
 module LogExpFunctions
 
-export xlogx, xlogy, logistic, logit, log1psq, log1pexp, log1mexp, log2mexp, logexpm1,
-    log1pmx, logmxp1, logaddexp, logsubexp, logsumexp, softmax!, softmax
-
 using DocStringExtensions: SIGNATURES
-
 using Base: Math.@horner, @irrational
 
+export loghalf, logtwo, logπ, log2π, log4π
+export xlogx, xlogy, logistic, logit, log1psq, log1pexp, log1mexp, log2mexp, logexpm1,
+    softplus, invsoftplus, log1pmx, logmxp1, logaddexp, logsubexp, logsumexp, softmax,
+    softmax!
+
 include("constants.jl")
 include("basicfuns.jl")