0.5.1
Added: Mass paste
Tweak: Some extra info is displayed in the tree view to save having to click on each record individually

0.5
Added: TESsnip can now read XXXX subrecords, and correctly write them back out again when saving
Added: Groups contained inside other groups are no longer removed when the file is read in (i.e. the exact record structure is now preserved)
Added: The ability to edit the flags in record headers
Added: Flags and FormIDs are given in the record descriptions
Tweak: Records which are read in compressed are now written back out uncompressed (makes size calculations easier)
Fixed: Possible corruption of size information in record headers.
Removed: TESsnip no longer lets you merge whole plugins together. (They almost invariably ended up broken. Use TES4PLUGIN instead)

0.4
Added: TESsnip can now tell if a record is compressed by reading the header instead of guessing
Added: TESsnip will now snip out XXXX subrecords and the following oversized subrecord instead of just crashing

0.3
Added: The ability to edit compressed records
Fixed: No longer crashes when loading plugins containing compressed records
Fixed: Saving a plugin while a subrecord is selected no longer changes the subrecord name

0.2
Added: The ability to merge plugins (Cannot yet cope with leveled lists)
Added: The ability to edit the data contained in subrecords
Tweak: The save button is available even if a record is selected instead of the parent plugin.
Fixed: Crash when loading plugins containing CELL records
Fixed: Crash when clicking save with no plugin selected

0.1
Initial release. Crashes if you try and open oblivion.esm. Can handle small plugins, and can even merge levelled lists, although it's probably faster to recreate them by hand.