[ovs-dev] OVN/OVS Split POC: version 2

[Mark Michelson]

I've once again rolled another OVN/OVS split version. It can be found at 
https://github.com/putnopvut/ovn_mk2.git

The main changes between this and the old split POC are as follows:

* This is based on a much newer build of OVS master. Therefore, build 
errors people had with dhparams.c *should* be cleared up.

* This fixes errors with manpages.mk generation/checking, so there is no 
need to do a pointless `touch` of manpages.mk during the build process.

* In many cases, rather than hard-coding paths to OVS, we use variables. 
This isn't universally applied, but it's used for the locations of C 
headers, libraries, and manpages.

Please give this a look and let me know what you think.