Last commit caused -xobjective-c to be passed during linking on
Mac, causing object files to be treated as source files. Add a
-xnone flag to AM_LDFLAGS, canceling the effect of -xobjective-c.
Additinally, add a -xobjective-c++ flag to AM_CXXFLAGS, so that we
can use Objective-C in C++ files on Mac, if we ever need to.
On Mac, pass -xobjective-c to the compiler through AM_CFLAGS, not
AM_CPPFLAGS, so that it's only used for C sources, and not C++
sources. In the latter case, it clashes with the -std=... flag,
spewing an error. Thanks, Partha :)
Move gimp-debug-tools.c from tools/ to a new app-tools/ subdir,
which should contain external tools needed by app/, and which is
built *after* app/ (unlinke tools/). This allows gimp-debug-tool
to depend on libapp and libappwidgets, instead of on actual source
files from app/. Building sources from app/ in another subdir
screws with the distclean rules, and breaks distcheck.