[petsc-dev] additional changes to IS interface

[Barry Smith]

   I have pushed what I hope are my last changes to IS for awhile. 

1)   ISCreateBlock() now takes the PetscCopyMode argument (like ISCreateGeneral()) allowing reuse of the index data without a copy 


2)   ISCreateBlock()), ISBlockSetIndices() and ISBlockGetIndices() now work with indices relative to the block rather than the individual entries, for example If you wish to index the values {0,1,4,5}, then use
   a block size of 2 and idx of {0,2}. (It previously was idx of {0,4}. So make sure you update any of your code that uses the Blocked indices. This was to make consistent with usage in Vec/MatSetValuesBlocked() etc and is (argued by some and I agreed) a more reasonable paradigm.

3) There now exists ISToGeneral() instead of only ISStrideToGeneral().


  Happy computing,

   Barry