Merge branch 'develop' of https://git.rwth-aachen.de/ita/ITABase into...

Merge branch 'develop' of https://git.rwth-aachen.de/ita/ITABase into features/splines_and_piecewise_polynomials

Manually solved conflicts in _SourceFiles.cmake

# Conflicts:
#	include/ITABase/_SourceFiles.cmake
#	src/ITABase/_SourceFiles.cmake

include/ITABase/_SourceFiles.cmake

@@ -6,7 +6,6 @@ set( SubDirs Math )
 
 set( DirFiles	
 	ITAProgress.h
-	
 )
 
 if( ITA_BASE_WITH_JSON_SUPPORT )

src/ITASampleFrame.cpp

@@ -583,7 +583,7 @@ float ITASampleFrame::Normalize()
 	findPeak( &c, &s );
 	float fP = m_vChannels[ c ][ s ];
 	for( int i = 0; i < m_iChannels; i++ )
-		m_vChannels[ i ].div_scalar( fP );
+		m_vChannels[ i ].div_scalar( std::abs(fP) );
 
 	return fP;
 }