Update build for Ubuntu 12.10. 12.04 seems to no longer compile

Summary: Dave Watson put this in github a few months ago.

Test Plan: None

Reviewed By: delong.j@fb.com

FB internal diff: D912681

README

@@ -36,7 +36,7 @@ Dependencies
 
 - additional platform specific dependencies:
 
-  Ubuntu 12.04 64-bit
+  Ubuntu 12.10 64-bit
     - g++
     - automake
     - autoconf
@@ -44,10 +44,7 @@ Dependencies
     - libtool
     - libboost1.46-all-dev
     - libgoogle-glog-dev
-        This package has been removed from 12.04 -- use the one from 11.10
-    - gflags (packages need to be downloaded from below)
-        http://gflags.googlecode.com/files/libgflags-dev_2.0-1_amd64.deb
-        http://gflags.googlecode.com/files/libgflags0_2.0-1_amd64.deb
+    - libgflags-dev
     - scons (for double-conversion)
 
   Fedora 17 64-bit