fix(browser): fixing browser property in package.json

Updated package.json browser and added prepublishOnly script,
and added browser_build folder to .gitignore.

Author: aydrian

.gitignore

@@ -8,6 +8,7 @@ node_modules/
 
 output
 build
+browser_build
 .bin
 npm-debug.log
 builderror.log