It is actually a bad idea to use noinst_PROGRAMS for build tools,
because it adds a $(EXEEXT). It is best to override the all target
with all-local to trigger the tool build.
This will hopefully help resolve the circular dependency between
libgtk linking against inspector/libgtkinspector and inspector/
needing extract-strings from gtk/.
I didn't preserve the EXEEXT decorations in this operation -
automake gave me stern warnings about it, so I just dropped them
all. Somebody who cross-builds GTK+ will have to reconstruct this.