File agg-gpc.patch of Package agg

--- include/Makefile.am
+++ include/Makefile.am
@@ -1,6 +1,13 @@
 SUBDIRS = ctrl util platform 
 
 aggincludedir = $(includedir)/agg2
+
+if ENABLE_GPC
+GPCHEADERS = agg_conv_gpc.h
+else
+GPCHEADERS =
+endif
+
 agginclude_HEADERS = \
 	agg_alpha_mask_u8.h          agg_glyph_raster_bin.h          agg_span_allocator.h \
 	agg_arc.h                    agg_gsv_text.h                  agg_span_converter.h \
@@ -27,7 +34,7 @@
 	agg_conv_contour.h           agg_rasterizer_scanline_aa.h    agg_trans_affine.h \
 	agg_conv_curve.h             agg_rasterizer_sl_clip.h        agg_trans_bilinear.h \
 	agg_conv_dash.h              agg_renderer_base.h             agg_trans_double_path.h \
-	agg_conv_gpc.h               agg_renderer_markers.h \
+	$(GPCHEADERS)                agg_renderer_markers.h \
 	agg_conv_marker.h            agg_renderer_mclip.h            agg_trans_perspective.h \
 	agg_conv_marker_adaptor.h    agg_renderer_outline_aa.h       agg_trans_single_path.h \
 	agg_conv_segmentator.h       agg_renderer_outline_image.h    agg_trans_viewport.h \
@@ -45,3 +52,4 @@
 	agg_font_cache_manager.h     agg_scanline_u.h                agg_vpgen_segmentator.h \
 	agg_gamma_functions.h        agg_shorten_path.h \
 	agg_gamma_lut.h              agg_simul_eq.h
+