Security improvements
Merge pull request #715 from bartekn/security-improvements

Security improvements
Special case where issuer is found in last path
Merge pull request #734 from stellar/counterparty

Use true issuer address
force them to enter their FB pw
Add the username to the wallet if it is missing
Merge pull request #755 from stellar/fix-missing-username

Add the username to the wallet if it is missing
Merge branch 'master' into multi-currency