I changed the filename of the patch to ZOOKEEPER-1178.patch like you said.
As for your other questions:
1) This is better than using the ant-eclipse.jar as it doesn't just try to detect the project structure, you can actually have the real .project and .classpath files checked in. Using ant-eclipse.jar, you cannot do that as the .classpath file will contain absolute paths to some of the jar the are dependencies for the build, which means that .classpath contains local settings. Using this patch with the Apache IvyDE extension for eclipse allows the .classpath to refer to the Ivy deps in a way that doesn't involve putting absolute paths into the .classpath file. Compare the .classpath from a newly generated zookeeper eclipse project with "ant eclipse" vs. the .classpath in this patch. The line containing the string IVYDE is the important one in the new file in the patch. Also, having the real .project file checked in should allow us to have more complex configuration out-of-the-box for Eclipse users, such as having the code style pre-configured.
2) I would love to do so.
3) Ok, that kinda sets a new president for where files like this should go. Is that okay with others in the project?
With regard to this patch, I honestly think that the .eclipse and .classpath files should eventually be moved to the root of the project so that anyone using eclipse can just import the project. We could even include a code style and other project settings that all eclipse users should have. The user specific .settings directory should not be included in the repo, of course. AFAICT, the only thing stopping that from being realistic today is having the ant-eclipse.jar generate a .classpath with absolute paths, which this patch addresses at the cost of requiring the IvyDE extension. However, I think that requiring Eclipse developers to use the IvyDE extension is a pretty small barrier since (a) zookeeper already has an ivy configuration and (b) it's an free and open source (Apache even) extension.