[issue-7][fix] Use absolute path to Ruby 1.8.7 binary in shebang

Force use the 1.8.7 interpreter that shipped with Mac OS < 10.9 and all
TM libraries depend on
[command][fix] Validate syntax command not aware of singular word form "triple"

Validate syntax command broke, when Turtle document only contained a
single triple. Rapper output processing wasn't aware of singular word
form "triple".
[command][fix] Prevent interpreter warning on method overload "[]"