Added the ability to sync tags.
Merge pull request #1 from bjaanes/master

Pull request with my latest changes. Some memory leaks fixed and some html and enml.
Merge branch 'master' of https://github.com/baumgarr/Nixnote2
Correct some drag & drop issues when changing tag hierarchy.
Add ability to sync user owned notebooks
Cleaned up some if-statements in the filterengine, should make it more readable and probably a little bit more effecient as well