onewire: preparations for protocol separation between link and network layers
onewire: placing protocol layers into separate directories
onewire: the split of the protocol into layers works now
onewire: combined reset and presence detect events, avoid unneeded overdrive exit message
onewire: updates to link layer timing
onewire: added transport layer decoder, it does not do much for now
onewire: updated documentation
onewire: added new transport layer commands
onewire: fixed an issue caused by renaming a transport layer command
srd: onewire_link: Cosmetics, simplifications, doc fixes.
srd: onewire_network: Cosmetics, simplifications, doc fixes.
srd: onewire_link/network: Reduce nesting level.

Also, some additional cleanups.
srd: onewire_link/network: Fix annotations, small cleanups.

The annotation types are 'Text' and 'Warnings', not 'Link' etc. as the
annotations of the onewire_link PD (for example) are already clearly
from the link layer. The annotation types should be different things/formats
of a specific PD's annotation output instead (like "Celsius" / "Kelvin"
for some temperature sensor, for example).
srd: onewire_network: Fix typo, command is 0x69.

The 'Overdrive match ROM' command is 0x69, not 0x6d. Verified in various
datasheets and the original 1-Wire/iButton spec.
srd: Rename onewire_transport to maxim_ds28ea00.

It doesn't make sense to have one "generic" onewire_transport PD, as
this layer is very much device-specific and such a generic PD would
have to contain an accumulation of all possible features and commands
and handling code of all existing (now and in the future) 1-Wire
devices, which is neither possible nor useful nor elegant.

There are (for example) 1-Wire thermometers, RTCs, EEPROMs,
special-purpose security chips with passwords/keys, battery monitoring
chips, and many many others. They all have a different set of features,
commands and command codes, RAM areas/sizes/partitioning/contents,
protocols, and so on.

Thus, the layering for 1-Wire PD stacks should look like this:

 onewire_link -> onewire_network -> <specificdevice>

Examples:

 onewire_link -> onewire_network -> maxim_ds28ea00 (special thermometer)
 onewire_link -> onewire_network -> maxim_ds2431 (1kbit EEPROM)
 onewire_link -> onewire_network -> maxim_ds2417 (RTC)
 onewire_link -> onewire_network -> maxim_ds2762 (battery monitor)
 onewire_link -> onewire_network -> maxim_ds1961s (SHA-1 eCash iButton)
 and so on...

So, renaming onewire_transport to maxim_ds28ea00. The non-DS28EA00
specific code will be dropped and/or moved to other PDs on top of
onewire_network later.
srd: maxim_ds28ea00: Fix to only handle DS28EA00.
srd: maxim_ds28ea00: Cosmetics, cleanups.
srd: maxim_ds28ea00: Factor out putx(), small fixes.
srd: onewire_link: Annotations shouldn't be ALLCAPS.

While states in the PD should be ALLCAPS per guidelines (for
consistency), the annotations that a PD outputs (and are shown in a
console via sigrok-cli or in a GUI) should be "normal" human-readable
text/formatting usually, i.e. not ALLCAPS.
sr: chronovu-la8: fix segfault on discovery

If the uninitialized value didn't happen to contain 0, and there
is no Chronovu LA8 connected, the la8_close() causes a segfault
in libftdi.