[tlbuild] automate and localize full (support files as well) tex package build/install

[John Z. Bohach]

I am very new to this Texlive build system, please excuse my ignorance, 
but I have several questions:

1) does the tl-install download source code and build it on the local 
machine?  If not, how is binary compatibility assured against a given 
runtime environment (glibc, gcc, binutils, etc.)

2)  if source code is downloaded, is it possible to "freeze" the 
install, take a snapshot of the top level download directory, and build 
it later, in some automated fashion, without going through tl-install 
again, at least in a way that let's me be disconnected from the 
internet to finish the build?

I understand that the texlive binaries can be built from the source 
tarball, but there's a note that says they must be installed under 
Master/arch/ of a previous tl-install area to be useful.  That's fine, 
but where do the rest of these support files come from, and were those 
support files built from source locally as well (see question 1) 
above).  At some point, those support files were built from source by 
somebody.  Who can I thank and who I should I emulate and venerate?  
Where can I get more information on building the full Master/ tree, 
support files included, from source?  Am I insane?  Can I can get back 
to you on that?

Thanks,
John

<--  Don't ask me why I want to do this...you'll just get a 
terse "because..."  I'm not a philosopher...why ask why? -->