Merge pull request #25 from kossebau/properlySaveFontFaceDecls

Properly load and save font-face declarations, to some degree at least
Move cloning of master pages into own method

Also:
* rename methods for more precision:
    setFramePosition -> setDrawElementPosition
    modifyImages -> modifyDrawElements
    getMasterPage -> getMasterPageElement
* move the var shadowContent into proper place