added push_lhs command returning undef for the time
remove space after comma that follows lhs
add output file for basic_test target
push_lhs command now returns the right lhs id's
Work on push_lhs command: t+
remove debug printing
return undef for nulling symbols and check negative symbol ID's per Jeffrey Kegler comments
Merge pull request #86 from rns/lhs_desc

lhs array descriptor