Add hb_version symbol and .version member

hb.symbols

@@ -45,5 +45,7 @@ _hb_set_destroy
 _hb_set_get_population
 _hb_set_next_many
 _hb_shape
+_hb_version
+_hb_version_string
 _malloc
 _free

hbjs.js

@@ -533,15 +533,24 @@ function hbjs(Module) {
     return trace;
   }
 
+  function get_version() {
+    var versionPtr = exports.hb_version_string();
+    var version = utf8Decoder.decode(heapu8.subarray(versionPtr, heapu8.indexOf(0, versionPtr)));
+    return version;
+  }
+
   return {
     createBlob: createBlob,
     createFace: createFace,
     createFont: createFont,
     createBuffer: createBuffer,
     shape: shape,
-    shapeWithTrace: shapeWithTrace
+    shapeWithTrace: shapeWithTrace,
+    version: get_version(),
   };
-};
+}
 
 // Should be replaced with something more reliable
-try { module.exports = hbjs; } catch(e) {}
+try {
+  module.exports = hbjs;
+} catch (e) {}

test/index.js

@@ -247,3 +247,10 @@ describe('shape', function () {
     });
   });
 });
+
+describe('misc', function () {
+  it('get version string', function () {
+    const version = hb.version
+    expect(version).to.match(/^\d+\.\d+\.\d+$/);
+  });
+});