added example to xChunk, improved performance of xLambda
added kiwi parametres to xLambda
added kiwi parametres to unary functions
factored out a large function in xLambda
simplified xLambda
fixed missing environment setting.
added support for mixed underscore and normal function
added better parametre validation
fixed error messages made by xLambda
minor speedup of xlambda
significantly sped up the unary function case.
bumped version
mend
Merge branch 'develop' into releases