Update bootstrap.touchspin.js

1. Add using input "data-" attributes for plugin;
2. Replace jQuery "bind" method with "on";
3. Replace jQuery "blur()" method with "on('blur')";
4. Replace curly brace on the one line with function declaration;
Merge pull request #16 from amid2887/patch-2

Update bootstrap.touchspin.js: Add "data-" attributes options