Throw MethodError instead of StackOverflowError for gamma, loggamma, and logabsgamma (#347)

* Throw `MethodError` instead of `StackOverflowError` for `gamma`,`loggamma` and `logabsgamma`

* Bump version

* Fix `logabsgamma(::Float16)`

* Remove whitespace

* Dispatch to internal functions

According to @stevengj's suggestion

* Load `logtwo`

* Fix tests

* Fix type stability issue

Author: devmotion

src/SpecialFunctions.jl

@@ -9,6 +9,7 @@ using IrrationalConstants:
     inv2π,
     invsqrt2,
     invsqrt2π,
+    logtwo,
     logπ,
     log2π