contrib: bump boost to 1.64

* attempt to fix crash on Android
* move from sourceforge to bintray for hosting

Change-Id: Iadf789293b7302c768f79bd8388b25049bd44d51
Reviewed-by: Anthony Léonard <anthony.leonard@savoirfairelinux.com>

contrib/src/boost/SHA512SUMS

-a1c7338e2d2dbac8552ede7c554640d22cbb2fda7fbc325dc3cdcb51e769713626695426ffc158cbe0e1729dd9a7b5ad18af4800d74e24539e8d8564268c2b9d  boost_1_61_0.tar.bz2
+68477f148f61be617552ef48559c5c2cb90d42264cabd6d5e87215d0d5024b48fca27c4afcfc1f77e490c6220d44fb1abdf0a53703867a2e4132c2857f69fedf  boost_1_64_0.tar.bz2

contrib/src/boost/rules.mak

 # Boost
-BOOST_VERSION_1 := 1.61.0
-BOOST_VERSION_2 := 1_61_0
-BOOST_URL := $(SF)/boost/files/boost/$(BOOST_VERSION_1)/boost_$(BOOST_VERSION_2).tar.bz2/download
+BOOST_VERSION_1 := 1.64.0
+BOOST_VERSION_2 := 1_64_0
+BOOST_URL := https://dl.bintray.com/boostorg/release/$(BOOST_VERSION_1)/source/boost_$(BOOST_VERSION_2).tar.bz2
 
 PKGS += boost
 
@@ -55,7 +55,6 @@ ifdef HAVE_ANDROID
 	cd $< && echo "<archiver>${HOST}-ar" >> user-config.jam
 	cd $< && echo "<compileflags>-DANDROID" >> user-config.jam
 	cd $< && echo "<compileflags>-D__ANDROID__" >> user-config.jam
-	cd $< && echo "<compileflags>-I$(ANDROID_TOOLCHAIN)/include/c++/4.9" >> user-config.jam
 	cd $< && echo ";" >> user-config.jam
 endif
 ifdef HAVE_IOS