Client: Add ERC20 Asset Management to DAO

[kylerchin]

Allow DAO to manage ERC20 Assets use them just like ether. All functionalities can be used with other ERC20 compatible assets.

This will be useful in the future, as companies will need to manage many types of assets and it also gives more attention to Aragon.

[izqui]

We agree this is very important. The Finance app for v0.5 (replacing current Accounting) will support managing ERC20 tokens (Even ether is handled as a wrapped token)

Closing as it is already an issue on aragon-apps.

[kylerchin]

@izqui Thanks for the heads up! The community needs more peeps like you! Forward Aragon!