added friends panel
Revert "minor commits"

This reverts commit fbe93e2f40600658d3735de4e403620ab6354a25.
Revert "Revert "minor commits""

This reverts commit 15f4eece2b0a408a05a44667b9f09274b67107e6.
Revert "minor commits"

This reverts commit fbe93e2f40600658d3735de4e403620ab6354a25.
deleted panel-friend
inserted panel-friend
inserted selectionChanged functoin
added navigation from friend to panel-friend
added friend attribute
bound friend to calendar
updated chat
deleted unnecessary code
updated user check
check for selection existence