Log Message:
Changes 2.4.18:

GMime 2.4 has had a number of API changes since GMime 2.2. To start, ALL public
APIs that used to use off_t in GMime 2.2 now use gint64 so that the API and ABI
do not change based on whether or not large file support is enabled.

In addition, all of the functions marked as deprecated in 2.0 and 2.2 were
removed (usually they had equivalent functionality in a parent class).

Many functions have also been renamed for better clarity and/or consistency.
For convenience, GMime 2.4 source packages include a shell-script to aid in
porting applications using GMime 2.2 (should work for most GMime 2.0
applications as well) to the 2.4 API. You can find this script under the
tools/ directory, named `gmime-port-2-2-to-2-4.sh'.

This script won't fix everything, but it should help quite a bit.