Move papers from operating systems to virtual machines (#519)

* Some papers where moved from operating systems to virtual machines section.

operating_systems/README.md

@@ -6,22 +6,9 @@
 
 * [The Scalable Commutativity Rule: Designing Scalable Software for Multicore Processors](https://people.csail.mit.edu/nickolai/papers/clements-sc.pdf)
 
-## System Virtualization
-
-* [Xen and the Art of Virtualization](http://www.cl.cam.ac.uk/research/srg/netos/papers/2003-xensosp.pdf)
-
-* :scroll: [kvm: the Linux Virtual Machine Monitor](kvm-linux-virtual-machines-monitor.pdf)
-
-### Live migration of Virtual Machines
-
-* :scroll: [Live Migration of Virtual Machines](live-migration-of-virtual-machines.pdf)
-
 ## Jails and containers
 
 * :scroll: [Jails: Confining the omnipotent root.](https://us-east.manta.joyent.com/bcantrill/public/ppwl-cantrill-jails.pdf)
 
 * :scroll: [Solaris Zones: Operating System Support for Consolidating Commercial Workloads](https://us-east.manta.joyent.com/bcantrill/public/ppwl-cantrill-zones.pdf)
 
-
-
-

virtual_machines/README.md

@@ -1,5 +1,18 @@
+## Virtual Machines
+
 * [One VM to Rule Them All](http://lafo.ssw.uni-linz.ac.at/papers/2013_Onward_OneVMToRuleThemAll.pdf)
     - This is an exciting VM implementation that incorporates AST node rewriting and an optimizing compiler. It enables the implementation of, and excellent performance for, a wide range of languages.
 * [A Comparison of Software and Hardware Techniques for x86
   Virtualization](http://www.vmware.com/pdf/asplos235_adams.pdf)
     - virtualization theory background
+
+## System Virtualization
+
+* [Xen and the Art of Virtualization](http://www.cl.cam.ac.uk/research/srg/netos/papers/2003-xensosp.pdf)
+
+* :scroll: [kvm: the Linux Virtual Machine Monitor](kvm-linux-virtual-machines-monitor.pdf)
+
+### Live migration of Virtual Machines
+
+* :scroll: [Live Migration of Virtual Machines](live-migration-of-virtual-machines.pdf
+)