[trunk] Pictures added to a frame have a fixed initial size of 200x200

Trunk rev. 5282.

In function MuseScore::addImage() (file file.cpp, line 1700 and foll.), which implements the "Add | Picture" contextual menu command for a frame, the image size is set to a fixed 200x200 size; see line 1729:

s->setSize(QSizeF(200, 200));

Following discussion on dev list, this line should be removed. A patch will follow shortly (I need an issue number!)

M.