many organizational improvements to ~/.bashrc

bash is such an eclectic, sporadic, ad hoc, overladen language that all
but the most excellent script designs are collaterally encumbered
without any such conscious effort expended.  A great deal of thought and
care must be exerted in order to maintain excellence in a bash script.
Hopefully this is an iteration with movement in the direction of a
better design, or I'll give up some time in the future and switch to zsh
or fish