[Discuss-gnuradio] Build relief

[Tom Rondeau]

We just pushed an update to the build structure on master and next to
try to help with the memory consumption and possibly even build time.
I split gr-blocks up into multiple smaller swig builds and put them
together in the end. So you don't have to try to compile the gigantic
c++ file that swig created for it. Now, it's just 3 files a third of
gigantic.

This has definitely helped things on my systems, even the only with
less RAM that I could drive to its knees if I asked it to parallelize
the build too much. It should help everyone with build and swap
issues.

The technique is rather general and simple now that the full syntax
has been tested, so we could split it up even further or do similar to
other components if they grow too large. I'd rather not, but this is a
possibility.

Tom