(Feature) Add investment option without Metamask

[igorbarinov]

Rationale
There are customers of ICO who don't have Metamask of other Web3-injected wallet installed. In this issue, we add an option of buying tokens without using web3 injected wallet

Implementation
A list box with investment methods is added. It has two options Metamask and QR. Metamask is the default option if Metamask is present.

If the Metamask option is selected then on Invest button web3 event triggered.
If QR is selected then this set of controls and views is presented

• qr code. some research needs to be done:
  • check if QR code can have method id (data) embedded
  • check if QR code can have wallet and amount embedded
• label with the worth of selected tokens in ETH
• address
• control to copy the address. The toast should appear after successful copying
• progress bar. The page will poss crowdsale address for a number of tokens specified to invest on crowdsale contract. Should be a polling with 2(?) seconds
• memo to use data (protection from sending from exchanges)

After poll will catch the event the view will be changed to

It's possible that polling will get someone else investment for the same amount. We can add an additional parameter to buy() which will be emitted into the blockchain log. @vbaranov what do you think?

[fvictorio]

I think is better to start with a QR code just with the address. Encoding more information in a URI (that then can be converted to a QR) seems to be an open proposal: ethereum/EIPs#67.

[igorbarinov]

I agree, let's start with the address