tools: fix license-builder.sh for ICU

Modify tools/license-builder.sh to restore the Third-Party Software
licenses for ICU.

Also fix arguments to tail to work on Linux.

rvagg: modified sed command for ICU to replace tabs with spaces and
       remove whitespace at the end of lines

PR-URL: https://github.com/nodejs/node/pull/4762


Reviewed-By: Rod Vagg <rod@vagg.org>