Bump copyright year to 2020

The copyright year was last time updated in 2018. There is some cleanup
involved in this commit and the next copyright year update is supposed
to be simpler (i.e. substitute "-2020").

- Substitute occurrences of "-2018" with "-2020" using:
  git grep -I -l -e '-2018' -- ':(exclude)*.bak' | xargs \
  sed -b -i -e 's/-2018/-2020/g'

- Update special cases:
  CUEPlayer
    git grep -I -l -e 'Grigory Chudov 2010' -- | xargs \
    sed -b -i -e 's/Grigory Chudov 2010/2010-2020 Grigory Chudov/g'
  CUERipper
    git grep -I -l -e '2008-2009' -- | xargs \
    sed -b -i -e 's/2008-2009/2008-2020/g'
  CUETools, CUETools.FLACCL.cmd
    git grep -I -l -e '2008-2010' -- ':(exclude)*FlaCuda*' | xargs \
    sed -b -i -e 's/2008-2010/2008-2020/g'
    git grep -I -l -e '2010-2013' -- | xargs \
    sed -b -i -e 's/2010-2013/2010-2020/g'
  CUETools.ChaptersToCue
    git grep -I -l -e 'Grigory Chudov 2017' -- | xargs \
    sed -b -i -e 's/Grigory Chudov 2017/2017-2020 Grigory Chudov/g'
  CUETools.CTDB.EACPlugin
    git grep -I -l -e 'Grigory Chudov 2012' -- | xargs \
    sed -b -i -e 's/Grigory Chudov 2012/2012-2020 Grigory Chudov/g'
    git grep -I -l -e '2011-12' -- | xargs \
    sed -b -i -e 's/2011-12/2011-2020/g'
  CUETools.Codecs.FLACCL
    git grep -I -l -e '2009-2010' -- ':(exclude)*FlaCuda*' | xargs \
    sed -b -i -e 's/2009-2010/2009-2020/g'
  CUETools.eac3ui (BluTools)
    git grep -I -l -e '©  2018' -- | xargs \
    sed -b -i -e 's/©  2018/© 2018-2020 Grigory Chudov/g'
  CUETools.Flake
    git grep -I -l -e ' 2009-2014 Gr' -- | xargs \
    sed -b -i -e 's/ 2009-2014 Gr/ 2009-2020 Gr/g'
  CUETools.Processor
    git grep -I -l -e ' 2008-2013  Gr' -- | xargs \
    sed -b -i -e 's/ 2008-2013  Gr/ 2008-2020 Gr/g'
  CUETools.Ripper.Console
    git grep -I -l -e ' 2008-10 Gr' -- | xargs \
    sed -b -i -e 's/ 2008-10 Gr/ 2008-2020 Gr/g'
  CUETools.Ripper.Console, CUETools.Ripper.SCSI
    git grep -I -l -e ' 2008-13 Gr' -- | xargs \
    sed -b -i -e 's/ 2008-13 Gr/ 2008-2020 Gr/g'

  Single year entries: 2008, 2009, 2010, 2011, 2017, 2018
    git grep -I -l -e ' 2008 Gr' -- | xargs \
    sed -b -i -e 's/ 2008 Gr/ 2008-2020 Gr/g'
    git grep -I -l -e ' 2009 Gr' -- ':(exclude)*FlaCuda*' | xargs \
    sed -b -i -e 's/ 2009 Gr/ 2009-2020 Gr/g'
    git grep -I -l -e ' 2010 Gr' -- | xargs \
    sed -b -i -e 's/ 2010 Gr/ 2010-2020 Gr/g'
    git grep -I -l -e ' 2011 Gr' -- | xargs \
    sed -b -i -e 's/ 2011 Gr/ 2011-2020 Gr/g'
    git grep -I -l -e ' 2017 Gr' -- | xargs \
    sed -b -i -e 's/ 2017 Gr/ 2017-2020 Gr/g'
    git grep -I -l -e ' 2018 Gr' -- | xargs \
    sed -b -i -e 's/ 2018 Gr/ 2018-2020 Gr/g'

  Fix typo in copyright year of CUETools.Codecs.WMA/AudioDecoder.cs:
    Copyright (c) 20139 Grigory Chudov
    git grep -I -lw -e '20139' -- | xargs \
    sed -b -i -e 's/20139/2013-2020/g'

CUETools.CLParity/CLParity.cs

@@ -1,6 +1,6 @@
 /**
  * CUETools.CLParity: Reed-Solomon (32 bit) using OpenCL
- * Copyright (c) 2009 Gregory S. Chudov
+ * Copyright (c) 2009-2020 Gregory S. Chudov
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

CUETools.CLParity/Properties/AssemblyInfo.cs

@@ -10,7 +10,7 @@ using System.Runtime.InteropServices;
 [assembly: AssemblyConfiguration("")]
 [assembly: AssemblyCompany("")]
 [assembly: AssemblyProduct("CUETools.CLParity")]
-[assembly: AssemblyCopyright("Copyright © 2011 Gregory S. Chudov")]
+[assembly: AssemblyCopyright("Copyright © 2011-2020 Gregory S. Chudov")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
 

CUETools.CLParity/parity.cl

@@ -1,6 +1,6 @@
 /**
  * CUETools.CLParity: Reed-Solomon (32 bit) using OpenCL
- * Copyright (c) 2010 Gregory S. Chudov
+ * Copyright (c) 2010-2020 Gregory S. Chudov
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public