Add a test for EtPicture boxed type copying
Add G_SLICE=debug-blocks to test environment
Fix a double free when reading WavPack headers
Fix check for errors when writing WavPack tags
Fix double free in CDDB dialog error path
Use a stack-allocated buffer for WavPack tags
Simplify reading artwork description from Ogg tags
Avoid superfluous use of sizeof(char)
Use the GLib slice allocator where appropriate

When allocating structs, use the GLib slice allocator. Simplify some
allocation code to also zero-initialize the struct.
Use GIO when reading and writing list store files
Updated Hungarian translation
Use GIO when reading and writing ID3v2.4 files
Remove unnecessary ftruncate() wrapper
Add -Werror=return-type to compiler flags
Use const when fetching File_Name from an ET_File
Remove stray unused local CDDB code
Support album artist in WavPack tags
Use memset() to zero out the WavPack read buffer
Clear empty tag fields when saving WavPack tags

Refactor WavPack tag saving to use a new
et_wavpack_append_or_delete_tag_item() helper function. Call
WavpackDeleteTagItem() to delete a tag item if the item is empty.
Read the WavPack channel mask

Use WavpackGetChannelMask() to read the channel mask from the WavPack
header, and add a new et_wavpack_channel_mask_to_string() function to
format it for display.