Move the call to Buffer::errors("Parse") from BufferView::insertLyXFile to GuiView...

Move the call to Buffer::errors("Parse") from BufferView::insertLyXFile to GuiView::insertLyXFile.

Buffer::errors("Parse") is called 7 times in the whole project. 4 times from GuiView and three times from functions in other classes, but which are (almost) only called from the GuiView.

Buffer::errors is used to signal the GUI that there might be an error occuring, but what sense does it make if it is only called from the Gui ?

Isn't it better to let the function return wether it succeeded or not and let the GuiView take action in doing something with the possible errors.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@35911 a592a061-630c-0410-9148-cb99ea01b6c8