Make version 1.39.99 to prepare for next release

git-svn-id: http://svn.code.sf.net/p/xmlrpc-c/code@2657 98333e67-4a24-44d7-a75c-e53540dd3050
Fix comment

git-svn-id: http://svn.code.sf.net/p/xmlrpc-c/code@2658 98333e67-4a24-44d7-a75c-e53540dd3050
Add Pkg-config files

git-svn-id: http://svn.code.sf.net/p/xmlrpc-c/code@2659 98333e67-4a24-44d7-a75c-e53540dd3050