S3 Code Rewrite

Add code to read from S3 sources in the same style as the current writing code.
Merge the s3_write.c code into hfile_s3.c to put all the S3 code in the same
file.

This should simplify the S3 code and give us a little more flexibility in how
we use it.

Author: whitwham

config.mk.in

@@ -83,7 +83,7 @@ plugin_OBJS += hfile_s3_write.o
 
 CRYPTO_LIBS = @CRYPTO_LIBS@
 noplugin_LIBS += $(CRYPTO_LIBS)
-hfile_s3$(PLUGIN_EXT): LIBS += $(CRYPTO_LIBS)
+hfile_s3$(PLUGIN_EXT): LIBS += $(CRYPTO_LIBS) $(LIBCURL_LIBS)
 hfile_s3_write$(PLUGIN_EXT): LIBS += $(CRYPTO_LIBS) $(LIBCURL_LIBS)
 endif