Update the README and the CHANGELOG

Add a section on different standard libraries and add missing changes to
the changelog.

Author: ignisf

CHANGELOG.md

@@ -1,5 +1,8 @@
 ### Unreleased
 
+* Update upstream v8 version to 5.1.281.59
+* Make sure the patch set is applied in the correct order
+
 ### 5.0.71.48.4, 5.0.71.48.5 - 2016-05-13:
 
 * Enable the -fPIC flag for ARM

README.md

@@ -59,6 +59,16 @@ source-based distribution
 
 > This step release system is a workaround to carlhuda/bundler#1537
 
+##### Use with different standard C libraries
+
+The binary versions of this gem are linked against the most used standard
+library - glibc. Currently rubygems does not differentiate binary gems by
+standard library so we have no way of distributing different binaries for
+differnt standard libraries.
+
+What this means is that if you're running a distro that does not use glibc
+(like Alpine Linux), you'll have to use a source version of the gem.
+
 ### Requirements
 
 Building the v8 library from source imposes the following requirements: