updating README and documentation for SimGrid 3.19

README.md

@@ -28,7 +28,7 @@ And, one of the following:
 
 ## Dependencies
 
-- [SimGrid](http://simgrid.gforge.inria.fr/) - version 3.17 or higher
+- [SimGrid](http://simgrid.gforge.inria.fr/) - version 3.19 or higher
 - [Lemon C++ library](http://lemon.cs.elte.hu/) - version 1.3.1 or higher 
 - [PugiXML](http://pugixml.org/) - version 1.8 or higher 
 - [JSON for Modern C++](https://github.com/nlohmann/json) - version 3.1.0 or higher 

doc/getting_started.md

@@ -35,7 +35,7 @@ wrench-simple-wms-batch <PATH-TO-WRENCH-SRC-FOLDER>/examples/batch_hosts.xml <PA
 ## Understanding the Simple-WMS Examples      {#getting-started-example-simplewms}
 
 The `SimpleWMS` example requires two arguments: (1) a [SimGrid virtual platform 
-description file](http://simgrid.gforge.inria.fr/simgrid/3.17/doc/platform.html); and
+description file](http://simgrid.gforge.inria.fr/simgrid/3.19/doc/platform.html); and
 (2) a WRENCH workflow file.
 
 **SimGrid virtual platform description file:** 
@@ -44,7 +44,7 @@ of the platform on which an application execution is to be simulates. This is do
 a platform description file that includes definitions of compute hosts, clusters of hosts, 
 storage resources, network links, routes between hosts, etc.
 A detailed description on how to create a platform description file can be found
-[here](http://simgrid.gforge.inria.fr/simgrid/3.17/doc/platform.html).
+[here](http://simgrid.gforge.inria.fr/simgrid/3.19/doc/platform.html).
 
 **WRENCH workflow file:**
 WRENCH provides native parsers for [DAX](http://workflowarchive.org) (DAG in XML) 

doc/install.md

@@ -22,7 +22,7 @@ And, one of the following:
 
 ## Dependencies ##                  {#install-prerequisites-dependencies}
 
-- [SimGrid](http://simgrid.gforge.inria.fr/) -- version 3.17 or higher
+- [SimGrid](http://simgrid.gforge.inria.fr/) -- version 3.19 or higher
 - [Lemon C++ library](http://lemon.cs.elte.hu/) -- version 1.3.1 or higher 
 - [PugiXML](http://pugixml.org/) -- version 1.8 or higher 
 - [JSON for Modern C++](https://github.com/nlohmann/json) -- version 2.1.1 or higher 

doc/wrench_101.md

@@ -40,7 +40,7 @@ In WRENCH, a user simulation is defined via the wrench::Simulation class. Briefl
 a simulation is described by the following actions: 
 
 -# `init(int *, char **)`: Initialize the simulation, which parses out WRENCH-specific 
-and [SimGrid-specific](http://simgrid.gforge.inria.fr/simgrid/3.18/doc/options.html) 
+and [SimGrid-specific](http://simgrid.gforge.inria.fr/simgrid/3.19/doc/options.html) 
 command-line arguments.
 
 -# `instantiatePlatform(std::string &)`: Instantiate a simulated platform. It requires a