Create .lib files in the subdirs.

Patch by JonY <10walls at gmail dot com>

Originally committed as revision 13137 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1143,7 +1143,7 @@ case $target_os in
         EXESUF=".exe"
         SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
         SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
-        SLIB_EXTRA_CMD='-lib /machine:i386 /def:$$(@:$(SLIBSUF)=.def)'
+        SLIB_EXTRA_CMD='-lib /machine:i386 /def:$$(@:$(SLIBSUF)=.def) /out:$(SUBDIR)$(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.lib)'
         SLIB_INSTALL_EXTRA_CMD='-install -m 644 $(SUBDIR)$(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.lib) "$(SHLIBDIR)/$(SLIBNAME:$(SLIBSUF)=.lib)"'
         SLIB_UNINSTALL_EXTRA_CMD='rm -f "$(SHLIBDIR)/$(SLIBNAME:$(SLIBSUF)=.lib)"'
         SHFLAGS='-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.def) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base'