Preprocessor : added result of `git describe` to date_revision file

preprocessors.js

@@ -7,13 +7,16 @@ var fs = require('fs');
 date_last_commit = require('child_process')
     .execSync('git log -1 --format=%cd --date=short')
     .toString().trim()
+version = require('child_process')
+    .execSync('git describe')
+    .toString().trim()
 
 var sFileName = "src/date_revision.ts";
 
-fs.writeFile(sFileName, `export const jalhydDateRev = "${date_last_commit}";\n`, function(err) {
+fs.writeFile(sFileName, `export const jalhydDateRev = "${date_last_commit}";\nexport const jalhydVersion = "${version}";\n`, function(err) {
     if(err) {
         return console.log(err);
     }
 
-    console.log(`File ${sFileName} saved with date ${date_last_commit}`);
-});
\ No newline at end of file
+    console.log(`File ${sFileName} saved with date ${date_last_commit}, version ${version}`);
+});