New experimental IPMI 2.0 release of OpenIPMI is ready

This is a start of a new series of OpenIPMI, with support for IPMI 2.0 features. This is still experimental, but should be fairly stable for most users.

This has the following new features:

* RMCP+ support
* Support for the new IPMI 2.0 LAN parameters
* Support for custom RMCP+ protocol plugins
* Socket reuse. A single UDP socket is used for multiple connections. This should improve scalability by more than an order of magnitude.
* Statistics. Currently statistics are kept on LAN connections and SEL handling. More statistics can easily be added, feel free to send patches!

In the works is:

* Serial Over LAN (SOL) from Cyclades
* Firmware firewall configuration from Intel

Note that there are no user interface changes from OpenIPMI 1.4, and I plan to keep it that way.

A few caveats with this release:

There is no xRC4 support. There are problems handling certain situations, and I'm not sure what to do with them.

The RMCP+ portion of the spec has quite a few holes, and the ICTS test suite seems to have some bugs. I have workarounds for the errors for BMCs that are not spec compliant or where the spec is not clear. Current workarounds are:
* Some BMCs use the wrong value of ROLE(m) in the authentication for the RAKP3 message. Adding "-H rakp3_wrong_rolem" to the "domain open" command will work around this problem.
* There is some confusion in the spec as to whether the SIK or K(1) is uses to authenticate messages. OpenIPMI uses K(1) by default (this seems to be the most common choice). You can add "-H rmcpp_integ_sik" to use SIK instead.

RMCP+ is only known to work with the Intel SE7520BD2 motherboard with the management module installed. It requires the "-H rakp3_wrong_rolem" option to work correctly.

There are some other spec compliance issues that I have seem, but the workarounds are transparent to the user. Hopefully we can get the BMCs fixed and consistent and updated in the field and all the hacks can go away.