Fix compilation. We can't use config_* in mozilla so use the -DDATAPATH

projects/mozilla/Makefile.am

@@ -163,6 +163,8 @@ else
 # UNIX/Others platforms
 #
 
+CPPFLAGS_mozilla_EXTRA = -DDATA_PATH=\"$(pkgdatadir)\"
+
 npvlc_LTLIBRARIES = libvlcplugin.la
 
 npvlc = libvlcplugin$(LIBEXT)
@@ -170,8 +172,8 @@ npvlcdir = $(libdir)/mozilla/plugins
 SOURCES_support = support/npunix.c
 
 libvlcplugin_la_SOURCES = $(SOURCES_mozilla_common) $(SOURCES_support)
-libvlcplugin_la_CFLAGS = `$(VLC_CONFIG) --cflags mozilla`
-libvlcplugin_la_CXXFLAGS = `$(VLC_CONFIG) --cxxflags mozilla`
+libvlcplugin_la_CFLAGS = `$(VLC_CONFIG) --cflags mozilla` $(CPPFLAGS_mozilla_EXTRA)
+libvlcplugin_la_CXXFLAGS = `$(VLC_CONFIG) --cxxflags mozilla` $(CPPFLAGS_mozilla_EXTRA)
 libvlcplugin_la_LDFLAGS = `$(VLC_CONFIG) --ldflags mozilla` -module -avoid-version -shrext $(LIBEXT)
 libvlcplugin_la_LIBADD = $(LIBRARIES_libvlc) `$(VLC_CONFIG) -libs mozilla`
 # automake gets confused by the ../..