#207 added a testclass for setFancyIntervalInSearch()
#207 made some changes in setFancyIntervalInSearch()
#207 modified a test
#207 added the case in setFancyIntervalInSearch() if the first number has a letter and the second number has no letter
#207 Sb_StadtbildWindowSearch: switched to stadtbildSerieSearchStatement.setSingleImageNumber() and removed two unused ComboBoxes
#207 added the case if both numbers have the same digits, but only the first one has one letter
#207 added a test for that case
#207 added some test cases which expect an exception
Merge branch 'feature/207-impovements-stadtbildnumber-interval-search' into dev