fixed problem with multiline String in detailloanwindow
added ueberfällig lbl to detailloan
added stupid comment
test
fixed problem with return on same day
fixed problems with addLoanTable
fixed problems with loading bookDetail
fixed merge conflict
added addBookWindow
made adding of book possible
fixed problems with closing newBookWindow
fixed design problem of statistics on bookmain
made statistics on loanmain working
fixed problems with table in bookDetailwindow
renamed tablemodel
fixed some observer problems
fixed some problems
added controller for Windows
added support for books in windowcontroller
made WindowController for Loan working