GExiv2 image metadata handling library

Library initialisation — Functions that need to be called to set up the GExiv2 library.
Generic image metadata handling — Class to handle the various image metadata standards
Reading and writing metadata — How to read and write metadata from files and memory
High-level functions for specific information — A set of helper functions to simplify accessing specific information
Functions related to EXIF metadata — Functionality specific to the EXIF familiy of metadata information
Functions related to XMP metadata — Functionality specific to the XMP familiy of metadata information
Functions related to IPTC metadata — Functionality specific to the IPTC familiy of metadata information
Preview images — Class describing preview images (or thumbnails) that are part of the metadata.
Properties of preview images — Class describing properties of a preview image
Library version information — Utilities for querying the library version
Logging functionality — Utility functions related to GExiv2's and Exiv2's logging.