Fix 243

Still needs some polishing, but this is how it looks now:

![screenshot 2014-05-07 01 23 45](https://cloud.githubusercontent.com/assets/2974463/2898495/779111d6-d59f-11e3-9ba7-57c8e098637b.png)

1. The "convert" button alternates between m and whole for the selected coin and adjust values accordingly.
2. Showing appropriate names on the dropdowns, buttons and tags.
3. Validation of minimum values changes according to the amount valuation.
4. If the wallet contains MSC it's selected by default, balance of the selected address reflects on the tags appended to the inputs.

Needs functional testing on the sale offer creation.