compiler: update missing license text in open source code log4cpp

[Ravisha Neelakanthappa]

For the following header and c++ files, license text is missing. Per our request lop4cpp committer has added license text to latest log4cpp version 1.1. We need to do the same for our copy. Since we use older version of log4cpp(1.0) and has no plan to upgrade, we will add this text manually.

BufferingAppender.hh
Export.hh
FactoryParams.hh
HierarchyMaintainer.hh
LayoutsFactory.hh
LevelEvaluator.hh
Makefile.am
Makefile.in
NTEventLogAppender.hh
PassThroughLayout.hh
TriggeringEventEvaluator.hh
TriggeringEventEvaluatorFactory.hh
Win32DebugAppender.hh
config.h
convenience.h

AppendersFactory.cpp
BufferingAppender.cpp
DummyThreads.cpp
FactoryParams.cpp
LayoutsFactory.cpp
LevelEvaluator.cpp
Localtime.cpp
Localtime.hh
Makefile.am
Manipulator.cpp
MSThreads.cpp
NTEventLogAppender.cpp
OmniThreads.cpp
PassThroughLayout.cpp
PThreads.cpp
RollingFileAppender.cpp
SmtpAppender.cpp
TriggeringEventEvaluatorFactory.cpp