Make the package hackable and updatable

#### tl;dr

The goal is to allow user to fetch the latest updates from coalahtml main package and also let me hack on the local package. An ideal solution would be that allows both.
- Hackability
- Updates
#### Details

Imagine user has a local copy of coalahtml angular app which is generated the first time user runs `coala-html`. Let's call it `A`.
Now he didn't like certain feature and so he decided to make changes to `A` locally, so now it's `A` -> `A*`. Also user may want to fetch the latest changes from coalahtml main pacakge and Ideally any updates from coalahtml main package should be applied to `A*` keeping the local changes(applied by the user) intact and not overwriting it.
Now the sugegsted patch basically checks if the user asks for reload, if yes then just ignore the local changes and replace the local files with coalahtml main angular package files
that means `A*` -> `A`
Which user wouldn't want
User would rather want to keep `A*` and still apply the patch from main package.
otherwise keep the `A*` intact and just update the json configs

For reference the patch is at http://pastebin.com/TA8xqNB2
It doesn't work completely as there are flaws in this approach. Also I gave up working on this approach because we needed something better solution. The patch has been added to support the explanation above.

CC @Uran198

Review the current reload and update path for the generated Angular app, then compare it with the referenced patch at pastebin.com/TA8xqNB2. Define how upstream package changes can be applied without overwriting local edits, while preserving the existing A* files and updating JSON configuration where appropriate.

Written by the indexing model from the issue text.