Some folders are special and versioning should not look for metadata in
them. Folders like /net with automount enabled may take a long time to
answer I/O on their children, so
VCSFileProxy.exists("/net/.git") will freeze until it timeouts.
This method is called from org.netbeans.modules.versioning.core.util.Utils.isForbiddenFolder()
This does not mean however that whole subtree should be excluded from version control,
only that you should not look for the metadata directly in this folder.
Returns true if the given folder is among such folders.
folder - a folder to query
true if the given folder should be skipped when
searching for metadata.