Add QtInfoMsg

Add an 'info' message type that can be used for messages that are neither
warnings (QtWarningMsg), nor for debugging only (QtDebugMsg). This is
useful mainly for applications that do not have to adhere to the
'do not print anything by default' paradigm that we have for
the Qt libraries itself.

[ChangeLog][QtCore][Logging] QtInfoMsg got added as a new QtMsgType.
  Use the new qInfo(), qCInfo() macros to log to it.

Change-Id: I810995d63de46c41a9a99a34d37c0d417fa87a05
Reviewed-by: Jason McDonald <macadder1@gmail.com>