* nitpicks and small improvements in basicauth module
1:
roll two if statements into one, since err will be nil in the second case anyhow
2:
unlock cache mutex after reading the key, as this happens by-value and reduces code complexity
3:
switch cache sync.Mutex to sync.RWMutex for better concurrency on cache fast track
* allocate the right kind of mutex
7a3d9d81fe