Log Message:
-----------
remove ccache directory on failure, should stop any persistent ccache errors
use perl module calls for most file operations rather than calling out to the shell.
Modified Files:
--------------
client-code:
run_build.pl (r1.62 -> r1.63)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbuildfarm/client-code/run_build.pl.diff?r1=1.62&r2=1.63)