Include unistd.h only on *NIX and define items as necessary on Windows,
also replace instances of ssize_t with the GLib-equivilant gssize so to fix
the build on platforms that do not have ssize_t, such as Visual C++.
https://bugzilla.gnome.org/show_bug.cgi?id=711047
Very many testcases, some GLib tools (resource compiler, etc) and
GApplication were calling g_type_init().
Remove those uses, as they are no longer required.
https://bugzilla.gnome.org/show_bug.cgi?id=686161
Add GZlibCompressor:file-info property. If it contains a non-NULL
GFileInfo, and the compressor is in GZIP mode, the filename and
modification time from the file info are written to the GZIP header
in the output data.
Add GZlibDeompressor:file-info property. If the decompressor is in GZIP
mode, and the GZIP data contains a GZIP header, the filename and
modification time are read from it, stored in a GFileInfo, and the
file-info property is notified.
Bug #617691.
