boost: bump to version 1.57.0

Also add hash file.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/boost/boost.hash

@@ -0,0 +1,3 @@
+# From http://sourceforge.net/projects/boost/files/boost/1.57.0/
+md5	1be49befbdd9a5ce9def2983ba3e7b76	boost_1_57_0.tar.bz2
+sha1	e151557ae47afd1b43dc3fac46f8b04a8fe51c12	boost_1_57_0.tar.bz2

package/boost/boost.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-BOOST_VERSION = 1.56.0
+BOOST_VERSION = 1.57.0
 BOOST_SOURCE = boost_$(subst .,_,$(BOOST_VERSION)).tar.bz2
 BOOST_SITE = http://downloads.sourceforge.net/project/boost/boost/$(BOOST_VERSION)
 BOOST_INSTALL_STAGING = YES