Add tail-recursion support.
Add tail-recursion support.

yantrabuddhi/atomspace,inflector/atomspace,misgeatgit/atomspace,rodsol/atomspace,yantrabuddhi/atomspace,rodsol/atomspace,AmeBel/atomspace,yantrabuddhi/atomspace,AmeBel/atomspace,rTreutlein/atomspace,AmeBel/atomspace,AmeBel/atomspace,misgeatgit/atomspace,rTreutlein/atomspace,cosmoharrigan/atomspace,williampma/atomspace,williampma/atomspace,misgeatgit/atomspace,ceefour/atomspace,inflector/atomspace,cosmoharrigan/atomspace,rTreutlein/atomspace,yantrabuddhi/atomspace,cosmoharrigan/atomspace,ArvinPan/atomspace,rodsol/atomspace,inflector/atomspace,ceefour/atomspace,williampma/atomspace,rodsol/atomspace,AmeBel/atomspace,inflector/atomspace,ArvinPan/atomspace,ArvinPan/atomspace,misgeatgit/atomspace,ArvinPan/atomspace,yantrabuddhi/atomspace,rTreutlein/atomspace,williampma/atomspace,misgeatgit/atomspace,ceefour/atomspace,inflector/atomspace,rTreutlein/atomspace,ceefour/atomspace,cosmoharrigan/atomspace