Check if apr_pool_destroy handles nll pointers gracefully (SVN.cc code improvement)

[Jari Häkkinen]

In SVN.cc there are two blocks of code that looks something like this. Check if apr_pool_destroy can handle a null pointer, if so make the code use cleanup(err,null);

cleanup could be called if a null pool can be passed to svn_pool_destroy (which is just a #define to apr_pool_destroy svn_handle_error2(err,stderr,false,"svndigest:"); svn_error_clear(err); throw SVNException("setup_ra_session: svn_client_open_ra_session failed");

[Jari Häkkinen]

(In [191]) Fixes #81. Changed behaviour of the cleanup functionalities in the SVN class.