Added the ContactDetailsDialog-class, and implemented the showDetails()-method of the controller class.

Updated version string to 1.0-SNAPSHOT after merging from Master. Merged from master to get the readme.md file into develop.

Got the fatal:refusing to merge unrelated histories ERROR, and tried to resolve this error.

This reverts commit b2430d91

First beta version. All GUI added, with coupling to backend (displaying the content of the addressbook), but non of the actions implemented (add new contact, edit contact etc.)