[PATCH v2 0/7] Some user-friendliness changes

[Tom Tromey]

Here is v2 of my "user-friendliness" patch series.  I've added docs
and some minimal tests.

v1 is here:
https://sourceware.org/pipermail/gdb-patches/2020-April/167350.html

In this version, I reimplemented "set style startup" and
"set startup-quietly" to both use a generic facility to store
some parameters in an early startup file.  This makes it simpler
to add more such settings, should we want to.

Let me know what you think.

Tom