Adding images does not work with Windows Meta File format

[martinstuder]

Adding windows meta files to xls workbooks seems to generate corrupt files. Adding windows meta files to xlsx workbooks seems to work fine if originalSize is set to FALSE, but does not contain an image if originalSize is set to TRUE.

Reproducibe example:

wb = loadWorkbook("test.xls", create = TRUE)
createSheet(wb, name = "test")
createName(wb,name = "test", formula="test!$A$1:$C$6")
addImage(wb, filename = "C:/santa.wmf", name = "test", originalSize=FALSE)
saveWorkbook(wb)

[martinstuder]

Logged an issue with POI at https://issues.apache.org/bugzilla/show_bug.cgi?id=56928