[lmi] wx ./configure options

[Greg Chicares]

Vadim--It's been a while since we updated the ./configure options in
  install_wx.make
and I wonder whether there are any we should change. But first of all,
let me ask whether changing these options would make your work more
difficult...because I seem to recall that several years ago you wanted
some adjustments here that would let you reuse the same wx build for
other projects besides lmi, and I don't want to spoil that goal by
making casual changes that create incompatibilities for you without
adding much benefit for anyone else.

One change that I think shouldn't matter to you is to add
  --enable-no_deps
However, does that actually have any effect? Specifying it, I see:
  configure ... --disable-webview --enable-no_deps --enable-monolithic
  checking for dependency tracking method... gcc
but there's still a lib/.deps/ directory with 651 files (and I've made
very sure that any such directory created by an earlier build was
removed first).

[BTW, is there any way I can easily see which options were ignored?
On my first attempt, I mistakenly used this:
  --enable-enable-no_deps
and I didn't find an error message diagnosing my mistake.]

Is there a way to inhibit PCH? I ask because I believe we determined
that using gcc precompiled headers is actually a pessimization for lmi.
I see a 'wxprec.h.gch' that's 200 MB in case that's relevant.

Should we be using either or both of the following C++11 options?
  --enable-cxx11
  --with-cxx=11

Isn't the first of these two options:
  --enable-std_iostreams \
  --enable-stl \
implied by the second, so that the first may be removed? (I'm reading
  https://github.com/wxWidgets/wxWidgets/blob/master/configure.in
which says
  if test "$wxUSE_STL" = "yes"; then
  ...
  DEFAULT_wxUSE_STD_IOSTREAM=yes
.)

Currently I'm specifying
  --disable-compat24
which I think is silently ignored. I'm guessing that the defaults for
such 'compat' options are generally appropriate and should not be
overridden without a specific reason.