[Feature Request] show changed files according to git and enable diffing to git base version

[tienomeis]

There is a git client implemented purely in JS which could be used to retrieve the necessary git diff information: https://github.com/isomorphic-git/isomorphic-git

The file tree to the could then indicate for each file whether the file is equal or different to its git base version, e.g. text color for the ones with differences in blue.

The context menu of the current open file may then have an entry called "Show git diff" which opens a new read-only git-diff-view tab for this file. This way there may be multiple open git-view-tabs for different files at the same time, which are shown in the open files section (above the file tree).