e300: docs: Remove mention of E300 to not confuse people.

Signed-off-by: Moritz Fischer <moritz@ettus.com>
x300: Clarified FPGA compat error message
b200: serialized access to get_rx/tx_stream
docs: updating e310 front/rear panel images with latest drawings
tools: Backported kitchen_sink from master
utils: Backported latency bugfix from master
ks: different colours for OULSD status letters, timestamp 'Stopping' message
docs: Added link to the build wiki page
x300: Fixed FC window issue (was off by one)
b200: select valid 10 MHz ref (update GPIO) *before* updating ADF4001 external ref selection
b200: Fix for PLL setting not being applied intermittently

- Made the methods in adf4001_ctrl virtual
host/examples: rm'ed refs to d'boards, IF freq.

To reflect a reality where some USRPs don't have daughterboards,
and set_xx_bandwidth doesn't necessarily set an /IF/ bandwidth.
nirio: Address linking issues on OSX
e300,x300: Moved LED register space as not to overlap w/ GPIOs
e300,x300: Bumped FPGA compat number

- X300: FPGA compat 9
- E300: FPGA compat 5
3.8.1 Release

- Updated fpga-src submodule
- Updated version strings and images package