Merged revisions 21107-21109 via svnmerge from 
svn+ssh://bugman@svn.gna.org/svn/relax/trunk

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  r21107 | bugman | 2013-10-15 11:31:40 +0200 (Tue, 15 Oct 2013) | 5 lines
  
  Created the lib.check_types.is_complex() function.
  
  This is used to determine if a number is a Python or numpy complex type.
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  r21108 | bugman | 2013-10-15 11:34:11 +0200 (Tue, 15 Oct 2013) | 5 lines
  
  The lib.linear_algebra.matrix_exponential.matrix_exponential() function now uses lib.check_types.is_complex().
  
  This fixes the function for complex matrices.
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  r21109 | bugman | 2013-10-15 11:45:29 +0200 (Tue, 15 Oct 2013) | 3 lines
  
  Created a new unit test for lib.linear_algebra.matrix_exponential.matrix_exponential() for complex matrices.
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