Addon request: manage duplicated materials/nodegroups (datablocks)

I often find myself struggling with many material, material.001, material.002 etc… because i have to import objects from different files but sharing the same material. Same fate for nodegroups contained in those materials.
So as in title i’m looking for an addon that lets the user manage the process of finding and merging duplicated materials and nodegroups (or more generally datablocks). Are there any?

https://blenderartists.org/forum/showthread.php?80065-Eliminate-duplicate-materials-001-002-003-after-Appendhttp://blender.stackexchange.com/questions/55233/disable-material-duplication

Thanks for replying.
Deeevs! A ‘Merge datablock’ feature would be cool :wink:

Material Utils Specials has Merge Base Names option check that out. It’s available in 2.78
Select the objects, Shift+Q > Specials > Merge Base Names
Auto Rename/Replace will automatically search for the material without the suffix and replace the ones with them.
The upper option will take the selected material that is the data, strip it from the suffix (if it has any) and make it the new base.
So if you pick Material.007 to keep it’ll become the Material and other ones will be replaced with it.

Also material utils has the functionality to replace materials by name.