Revert:
commit 04b8559dff19056a229c11f3fb4c9fbc6b975117
Author: Wilfried Goesgens <w.goesgens@arangodb.org>
Date:   Fri Dec 5 17:36:38 2014 +0100

    remove our own icu from the configure - rely on v8 ones.

it doesn't work reliable that way.