8075492: adopt recent IGV
Summary: adopted recent sources, updated README, added build and run instructions; ignored IGV build files in Mercurial; adapted HotSpot Ideal graph printer to current IGV's data format schema; reintroduced control flow window and basic block layout
Reviewed-by: kvn, roland
Contributed-by: Andreas Woess <andreas.woess@oracle.com>, Bernhard Urban <bernhard.urban@oracle.com>, Christian Haeubl <christian.haeubl@oracle.com>, Doug Simon <doug.simon@oracle.com>, Gilles Duboscq <gilles.duboscq@oracle.com>, Lukas Stadler <lukas.stadler@oracle.com>, Peter Hofer <peter.hofer@jku.at>, Roland Schatz <roland.schatz@oracle.com>, Thomas Wuerthinger <thomas.wuerthinger@oracle.com>, Tom Rodriguez <tom.rodriguez@oracle.com>