[WIP] Perform development environment cleanup

[artkravchenko]

• Enable hot reloading of client-side .js chunks;
• Enable hot reloading of .less and .css chunks;
• Implement restarting of server-side API router on server related files update.

[coveralls]

Coverage decreased (-0.06%) to 57.218% when pulling 926ac3e on refactor/env into 4b392c6 on stable.

[coveralls]

Coverage decreased (-0.08%) to 57.198% when pulling 578f417 on refactor/env into 4b392c6 on stable.

[coveralls]

Coverage decreased (-0.06%) to 57.216% when pulling 9b398ce on refactor/env into 4b392c6 on stable.

[coveralls]

Coverage decreased (-0.06%) to 58.726% when pulling b706b2b on refactor/env into 331106a on stable.

[coveralls]

Coverage decreased (-0.06%) to 58.847% when pulling d55c9f9 on refactor/env into 77ec8de on stable.

[coveralls]

Coverage decreased (-0.06%) to 58.512% when pulling 2861d78 on refactor/env into 8422bb7 on stable.

[coveralls]

Coverage decreased (-0.06%) to 58.289% when pulling 205f99a on refactor/env into 233a973 on stable.

[coveralls]

Coverage decreased (-0.06%) to 59.443% when pulling 5effe49 on refactor/env into d947227 on stable.