Added methods for C call SetBasicCallback.
Need to check C side and documentation.
git-svn-id: svn://136.177.114.72/svn_GW/IPhreeqc/trunk@7884 1feff8c3-07ed-0310-ac33-dd36852eb9cd
Will try to revise so that the same callback works for Fortran and C.
git-svn-id: svn://136.177.114.72/svn_GW/IPhreeqc/trunk@7883 1feff8c3-07ed-0310-ac33-dd36852eb9cd