TreeFellerPlus

Features:

Automatically fells and chops down entire trees when the base of the tree is broken, no matter what the shape of the tree is (compatible with custom world generators)
Uses an optimized depth-first search to find the exact outline of the tree
Uses heuristics to prevent griefing
Passes tree fellings to other plugins, such as WorldGuard, Factions, and Towny, to further prevent exploitation and griefing
Detects and isolates each tree's leaves (enabled by default in the config) so that felling one tree will only break the leaves corresponding to that tree.
Comes with a documented config.yml

Permissions (v1.1+):

treefellerplus.use: Allows one to automatically fell trees. All players have it by default.
treefellerplus.reload: Allows one to execute /treefellerplus reload.

Notes:

Requires Java 7 or later.

Known Bugs:

In special cases trees that touch via leaves will both be felled. This is uncommon and its cause is unknown, but it will most likely be resolved in the next update.
If a player tries to fell a tree that touches another tree that hangs over it, then it may not be properly felled.

If you find any more bugs while using this plugin, please report them so that they may be resolved in the upcoming updates. Additionally, comments, feedback, and suggestions are always welcome.

TreeFellerPlus

Features:

View me on GitHub!