Followup: Adding a .classpatch check. Warn user if .classpath not found.

Change-Id: I877f817583e6393f1a486a8233c54aa397b3019c
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=499577
Signed-off-by: Lev Ufimtsev <lufimtse@redhat.com>