Add --content-disposition option

so that we save good file name when we downloading links like that:

`http://downloads.sourceforge.net/project/sqlitebrowser/sqlitebrowser/3.3/sqlitebrowser-3.3.0.dmg?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Fsqlitebrowser%2F%3Fsource%3Ddirectory&ts=1409141373&use_mirror=netcologne` 

and not getting file names like `sqlitebrowser-3.3.0.dmg?r=http%3A%2F%2Fsourceforge.net%2Fprojects%2Fsqlitebrowser%2F%3Fsource%3Ddirectory&ts=1409141373&use_mirror=netcologne`