New features for Extension manager

danames[CodePlex]
Adding the Following features to the Extension Manager:

push notification to tell people when updates are available to plugins version specific updates add support for updating Dotspatial dlls more robust backup system

Also Possibly:

make the extension manager run mostly outside of HydroDesktop (So as to update DotSpatial)
Allow update scripts\instructions (To delete/move files around)

Start by locating the Extension Manager implementation in the HydroDesktop repository and review how plugins and DotSpatial DLLs are currently installed or updated. The issue lists several independent feature ideas but names no files, tests, or agreed scope. Done would require breaking these ideas into specified requirements with an identified implementation and validation plan.

Written by the indexing model from the issue text.