Some default values differ between classic and normal sessions. We
used to implement this by overriding the shell's default values in
mini-extensions (or more precisely: reversing the shell's overrides).
Use a mode-specific overridesSchema instead, which has the advantage
that settings defaults will not change unexpectedly when extensions
are disabled/enabled (for instance during screen locks).
https://bugzilla.gnome.org/show_bug.cgi?id=701717
Classic mode should be visually distinct from the normal session,
so provide a mode-specific stylesheet which looks closer to the
familiar GNOME2 default theme.
https://bugzilla.gnome.org/show_bug.cgi?id=693169
The Makefile had two rules by which it could possibly have generated the
intermediate .in file (on the way from .in.in to .session) and it picked
the one that didn't contain the substitution for @libexecdir@.
Consolidate the rules into one that does all the needed substitutions.
https://bugzilla.gnome.org/show_bug.cgi?id=689756
