DebugStrOut - flush parameter type differs in declaration,documentation and usages

In stp.h flush parameter is uint:
```c++
typedef void  (*STP_CALLBACK_DEBUG_STR_OUT)  (const struct STP_BRIDGE* bridge, int portIndex, int treeIndex, const char* nullTerminatedString, unsigned int stringLength, unsigned int flush);
```

In documentation _StpCallback_DebugStrOut.html_ flush is bool type.

All usages inside _stp_log.cpp_ provide true/false as flush argument
