Github repository migration

As announced during the mviewer meetings, the github repositories of mviewer and mviewerstudio have moved at the beginning of the year.

You can find these two projects here: https://github.com/orgs/mviewer/repositories

Remember to update your forks and clones of both projects.

Examples for mviewer :
Before any changes, check what you need to change with the command:
git remote -v

Clone https:
git remote set-url origin https://github.com/mviewer/mviewer.git

clone ssh:
git remote set-url origin git@github.com:mviewer/mviewer.git

Fork https:
git remote set-url upstream https://github.com/mviewer/mviewer

Fork ssh:
git remote set-url upstream git@github.com:mviewer/mviewer.git