Responsive input box with placeholder

"Send" - "Amount" input box:

- Box is cleared, if box is focused and amount is 0.00000000
- Set amount to 0.00000000, if box loses focus and is empty
- Amount is formated to "_.________", if box loses focus and amount is
valid

Binary was signed by dexx@bitwatch.co (key id: 0xF5719832,
http://bitcoin-otc.com/viewgpg.php?nick=dexX7)