[UrJTAG-dev] PATCH: command "tdo" to complement "pod"

[eldentyrell <eld...@fa...>]

The "pod" command lets the user directly modify the TCK, TMS, and TDI
pins.  However, it does not appear that there is a complementary command
to directly read the TDO pin without doing any shifting.

Below is a patch against SVN 2026 that adds this command.

This is useful with devices that bend the rules of the JTAG protocol --
for example Xilinx FPGAs sometimes act as if they have an "infinitely
large" DR register for loading bitstreams.