Make the firmware download function available again

Apparently at least one person used hpilo_fw.py's download function.
It's now moved into hpilo_cli. This is also a good time to document the
various firmware tricks hpilo.py can do for you.
Write 64k chunks of ilo firmware
New firmware updates
Make the password protection in debug output optional
Do not escape passwords in generated XML

All iLO's have a bug where they don't properly unescape the password
field in LOGIN, ADD_USER and MOD_USER tags. Work around this by
monkeypatching etree._escape_attrib to not escape things we don't want
escaped and mark password data as 'do not escape me'. If we find other
fields with the same bug, these can now easily be marked as well.
Accept keword args in monkeypatched method
It's 2014
Delete untested functions that are no longer supported

Also add comments about XML processing instructions we may want to use,
but those need to be tested against current iLO versions.
Add federation group functions
Add missing ers functions
Add boot_mode (uefi or legacy) functions
Add provisioning profile functions
Add misc. missing/new functions:

get_encrypt_settings
get_hotkey_config
get_product_name
get_smh_fqdn
get_tpm_status
Version 2.8
Merge tag '2.8' into debian
New debian package