Remove Charles and category from .doap file

New category requirements seem to preclude gexiv2 from being listed.
Add programming language to .doap
Let exiv2 interpret all EXIF tags for interpreted strings: Bug #734861

This form of write() for ExifDatum is only available for EXIF.
Enable automake subdir-objects: Bug #736243
Support VPATH builds: Bug #736244
Add gexiv2/.dirstamp to .gitignore
Update to 0.10.2