save state of analysis

[sgratzl]

the current state of the analysis (regardless whether a local or a predefined file) should be stored in the IndexedDB of the browser such that the user can continue his/her analysis.

state needs to be updated upon hash change and when leaving the page.

https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB
http://dexie.org/