If you get blank screen during installing Revolution from SVN HEAD revision,
you should REBUILD core.
Do some simple actions:
1) copy \path\to\revo\_build\build.config.sample.php to \path\to\revo_build\build.config.php
2) fill right settings in it
3) load from browser
http://revo.site/_build/transport.core.php
4) start installation process from the begining.
