show credit balance in window title
make sure balance is cleared on logout and re-launch
fix rate of payment for assignments
output when pay-for-assignments is on
Merge branch 'master' of https://github.com/highfidelity/hifi into credits
fix floats that aren't actually floats
add back a missing space in AccountManager
Merge pull request #2904 from birarda/credits

display user's credit balance in window title