command-line.c: Use WHITESPACE instead of explicit strings
command-line.c: Use WHITESPACE instead of explicit strings

ampli/link-grammar,opencog/link-grammar,linas/link-grammar,linas/link-grammar,opencog/link-grammar,opencog/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,opencog/link-grammar,opencog/link-grammar,opencog/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,linas/link-grammar,ampli/link-grammar,linas/link-grammar,opencog/link-grammar,linas/link-grammar,linas/link-grammar,ampli/link-grammar,ampli/link-grammar,opencog/link-grammar,ampli/link-grammar,opencog/link-grammar,linas/link-grammar