package.sh: allow caching of git repositories
package.sh: allow caching of git repositories

VincentToups/lambdanative,attila-lendvai/lambdanative,emacstheviking/lambdanative,VincentToups/lambdanative,emacstheviking/lambdanative,youprofit/lambdanative,gale320/lambdanative,youprofit/lambdanative,gale320/lambdanative,emacstheviking/lambdanative,youprofit/lambdanative,attila-lendvai/lambdanative,VincentToups/lambdanative,youprofit/lambdanative,gale320/lambdanative,youprofit/lambdanative,emacstheviking/lambdanative,attila-lendvai/lambdanative,attila-lendvai/lambdanative,VincentToups/lambdanative,emacstheviking/lambdanative,gale320/lambdanative,VincentToups/lambdanative,attila-lendvai/lambdanative,gale320/lambdanative