Correct spelling errors [ci skip]

cmake/modules/DuneCxaDemangle.cmake

-# This Module checks whether the compiler supports the
+# This module checks whether the compiler supports the
 # abi::__cxa_demangle function required to
 # make the type names returned by typeid() human-readable
 #
-# It sets the a variable :code:`HAVE_CXA_DEMANGLE` with the result.
+# It sets the variable :code:`HAVE_CXA_DEMANGLE` with the result.
 #
 
 include(CheckCXXSourceCompiles)

dune/common/exceptions.hh

@@ -279,7 +279,7 @@ namespace Dune {
   class InvalidStateException : public Exception {};
 
   /*! \brief Default exception if an error in the parallel
-     communication of the programm occurred
+     communication of the program occurred
      \ingroup ParallelCommunication
    */
   class ParallelError : public Exception {};

dune/common/parallel/mpiguard.hh

@@ -107,7 +107,7 @@ namespace Dune
 
      You create a MPIGuard object. If an exception is risen on a
      process the MPIGuard detects the exception, because the finalize
-     method was not called.  when reaching the finalize call all
+     method was not called.  When reaching the finalize call all
      other processes are informed that an error occurred and the
      MPIGuard throws an exception of type MPIGuardError.