Memory leak when commiting tracks

[robbevp]

When fetching the tracks, the whole app is blocked on each commit. This takes progressively longer the more tracks are loaded.

You can clearly see this by:

• Added a console.debug at the end of setTracks. The gap between this debug and the store's debuger reporting will got bigger and bigger.

Tried:

• Just loading the tracks and not displaying any UI or using any computed values
• Freezing the tracks before adding them to the store
• Wrap the whole state.tracks in Object.freeze

Worked:

• Only update localStorage when one of the modules changed made a small improvement.

[robbevp]

@chvp If you have time to take a look. I can't seem to figure this out.
This uses the same structure as Accentor/web, but introduces a memory leak (or at least, a blocked UI while mutating the store) - probably due to a change in Vue's reactivity system.

[chvp]

Seems like you're running into vuejs/core#2380 / vuejs/vuex#1847