What happened with build.xml

Hello, I updated yesterday my xwiki sources and I see you've changed all the svn directories. The problem is that when I try to build it in Eclipse I can't find the build.xml file and also, I create a new project based on xwiki-platform-core and it gives me lots of errors in eclipse, like some files missing or some classes not found. Can anyone tell me how to build the standalone now that there is no build file? I would very much appreciate it. Thank you. Evelina