lcl: using fpcanvas EndCap

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40239 4005530d-fff6-0310-9dd1-cebe43e6787f
lcl: using fpcanvas JoinStyle

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40240 4005530d-fff6-0310-9dd1-cebe43e6787f
IDE: menu designer: prevent crash when all menu items were deleted, bug 23870

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@40241 4005530d-fff6-0310-9dd1-cebe43e6787f