More O_CLOEXEC support

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
Use a local allocator for the parsing buffers in ConfigFile

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
HandleTable can use a specialised Hash<>

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>