Dynamically scales DPI of TeX by area, fixes #75.
Added setting for presentationMode
Connected handlers for presentationMode
Mapped Up/Dn to PgUp/PgDn for presentation mode
Added presentation mode to Actions
Added GROUP_PRESENTATION_MODE to Actions
Fixed typo in setViewPresentationMode
Merge branch 'master' into addpoppler
Merge branch 'addpoppler' into glib_new