Include git

Author: embray

CHANGES.md

@@ -4,6 +4,9 @@ Changelog for the Windows Installer
 0.5.0 (unreleased)
 ------------------
 
+* Includes a copy of `git` in the SageMath Shell, so no need to install a
+  separate Git or integrate an existing Git for Windows installation.
+
 * Updates to use a few more Cygwin system packages rather than including
   Sage-specific copies, including:
 

cygwin-sage-runtime.list

@@ -7,6 +7,7 @@ gcc-core      	5.3.0-5
 gcc-fortran   	5.3.0-5
 gcc-g++       	5.3.0-5
 ghostscript     9.23-1
+git             2.21.0-1
 grep          	2.25-1
 hostname      	3.12-1
 ImageMagick     6.9.9.11-3