handling of autorepeated key events in picker machines


git-svn-id: svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1@1954 29e17f8d-cf37-471e-a288-72cc03a76eda
avoiding additional event filters for the internal overlays of a picker


git-svn-id: svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1@1957 29e17f8d-cf37-471e-a288-72cc03a76eda
clicking next to the slider handle fixed


git-svn-id: svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1@1960 29e17f8d-cf37-471e-a288-72cc03a76eda