[PATCH] Generic HDLC update

The attached patch updates generic HDLC to version 1.18.
FR Cisco LMI production-tested. Please apply to Linux 2.6. Thanks.

Changes:
- doc updates
- added Cisco LMI support to Frame-Relay code
- cleaned hdlc_fr.c a bit, removed some orphaned #defines etc.
- fixed a problem with non-functional LMI in FR DCE mode.
- changed diagnostic messages to better conform to FR standards
- all protocols: information about carrier changes (DCD line) is now
  printed to kernel logs.

Signed-Off-By: Krzysztof Halasa <khc@pm.waw.pl>