Update ssh known hosts
Add dedicated .ideavimrc

Reflecting new changes in the IDEA Vim plugin that always look to this
file vs directly looking at .vimrc. In my case, I simply source the
latter from the former.
Copy gitcommit.vim from its shared system location

Copy gitcommit.vim locally so as to make changes to it that will persist
across machines etc.
Set Vim textwidth to 72 for git commit messages

So that automatic hard wraps, 'gq' command, etc. work as expected.