Fix spell-check breaking note links

Fixes Bug 703664.
Fix note rename dialogo freeze

Sometime when renaming note and link rename is requested,
dialog does not have the proper focus and is not responsive.
Do not remove link tag when adding another

Fixes Bug 702160, Bug 702239.
Fix internal links merging with other links
Fix crash when disabling note add-in
Fix build without C++11

Fixes Bug 710949.