Debian patches. Please choose.

Hi. I'm not insisting on (almost) any of these, but I think they could improve your work with webdis. I'll describe commits one by one.

3156b53 — To make webdis free of race conditions while running tests as a part of automatic build process, I set webdis port to listen equal to zero that makes webdis listen on random available port. I then get the info on the port by parsing netstat and run tests against that port. See https://github.com/jollyroger/webdis/blob/debian/debian/test.sh for details. This patch allows me to configure port by using environment variables.

b1cda7e — add simple targets to run tests against running webdis instance.

46e872a — since Debian adds specific build flags, this patch allows me to redefine the ones set in the makefile for the whole build process.

8deffc7 — If libb64 is installed system-wide, It'll have 'b64' directory name, mostly under /usr/include. It'll be easier to redefine a single -I flag instead of patching the code to use system-wide library if available.

b616c37 — Request from the Debian Archive maintainers. Detailed description is in the commit message.

a712b07 — Dirty hack to make building against system-wide libraries much easier. This prevents unnecessary building of files that aren't going to be used if make is run with necessary parameters.