rework output's verbosity, make configurable

on Travis (10k lines output limit) make output to > $STDOUT file,
on local machine, print to console.

this is handeled by setting $_NTA_COMPILATION_OUTPUT variable (set to "Travis" for travis),
can be extended to other values.

I propose this because current behavior, stderr (warnings,errors) and stdout (compiled file, gcc cmd,...) are separate, so it's
useless for debugging.