Overwrite/Implement the missing default File methods

GridFile overwrites not all default methods, what result into errors when using them. So depending on what we can already provide I'll suggest the following implementation:

canRead() // return true
canWrite() // return true
isHidden() // return false
canExecute() // return false
deleteOnExit() // using JVM hooks could be too late and there are no pre-CacheStopped events, ideas welcome
renameTo(File dest) // check if dest is GridFile and rename if its true
setLastModified(long time) // just implement

// for them just throw unsupported operation ATM
getCanonicalPath() // until resolving .. and so on is available
getCanonicalFile() // until resolv path is avail
setReadOnly()
getUsableSpace()
getFreeSpace()
getTotalSpace()
setExecutable(boolean executable)
setExecutable(boolean executable, boolean ownerOnly)
setReadable(boolean readable)
setReadable(boolean readable, boolean ownerOnly)operation
setWritable(boolean writable)
setWritable(boolean writable, boolean ownerOnly)
toURI()
toURL()