#2 Add project name in build.xml

[Alessandro Vernet]

I just added a name to Ant project. This is typically
useful when running Ant from an IDE. In particular
IntelliJ IDEA will display the name of the project if
available, and just "build.xml" otherwise. When working
with multiple projects, it is nice to be able to see
their name, instead of "build.xml" for every project :).