missing first minor ticks fixed for certain logarithmic scales


git-svn-id: svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1@2042 29e17f8d-cf37-471e-a288-72cc03a76eda
explicitely show legend widgets after creation to avoid potential 
flickering


git-svn-id: svn://svn.code.sf.net/p/qwt/code/branches/qwt-6.1@2045 29e17f8d-cf37-471e-a288-72cc03a76eda