svn path=/main/trunk/; revision=13135
@type vartree: vartree instance
@param prev_mtimes: A dict of { filename:mtime } keys used by merge() to do config_protection
@type prev_mtimes: dictionary
+ @param fd_pipes: A dict of mapping for pipes, { '0': stdin, '1': stdout }
+ for example.
+ @type fd_pipes: Dictionary
+ @param returnpid: Return a list of process IDs for a successful spawn, or
+ in integer value if spawn is unsuccessful. NOTE: This requires the
+ caller clean up all returned PIDs.
+ @type returnpid: Boolean
@rtype: Boolean
@returns:
1. 0 for success