packaging: make client-install no longer depends on the mount.xtreemfs binary because it was made optional e.g., when compiling libxtreemfs for buildroot.
packaging: Fixed problems introduced in revision 1b9f05f5068d.

- Comments must not be indented or they will be run through the shell.
- Forgot "; true" and therefore the Makefile aborted if a conditional bash expression was not successful.
packaging: Makefile: Fixed indentation of comments. (Comments must not be indented or they will be interpreted by the executed shell.)
packaging: Makefile: Changed behavior if Fuse was not found. In that case, the compilation aborts instead of skipping the Fuse Adapter mount.xtreemfs.

The compilation of the FuseAdapter can be explicitly skipped with the new define "SKIP_FUSE".
packaging: Added packages and respective howto for buildroot.
disable http-servers for buildroot
clean up README and Config.in for buildroot
servers: DIR: Do not start the webinterface if -1 is specified as http_port.
servers: DIR: Catch exception if the receive of an UDP broadcast packet fails in the DiscoveryMsgThread.
servers: MRC: Do not start the webinterface if -1 is specified as http_port.
servers: OSD: Do not start the webinterface if -1 is specified as http_port.
packaging: Makefile: Added missing .jar files in uninstall target.