[Addon] Mirror Bone Constraints

Tracker page: https://projects.blender.org/tracker/index.php?func=detail&aid=36334

Although there is an existing workflow that allows constraints to be mirrored by duplicating, mirroring, and flipping the names of constrained bones, I became somewhat tired of doing this.

The script creates a button that mirrors the constraints of selected bones entirely in pose mode, eliminating the multi-step workflow. It also will flip names of appropriately named non-bone constraint targets so that, for example, if bone.r has a constraint specifying Empty.r as a target, when the constraint is mirrored to bone.l, the target will be changed to Empty.l.

Feedback appreciated!

EDIT: If anyone knows how to add a wiki page for the script and could tell me how to do it, that would be much appreciated.