Added external repo fpgahdl_xilinx from analog devices.
Added helper scripts for external repo fetch & sparse checkout.
Added HDMI versions of 7010 and 7020 projects for E16.
Requires pulling the external repo "fpgahdl_xilinx," see fpga/externals.
README updates.
Top-level README update.
Fixed nested lists.
Can't put a block quote within a list?
Yeah, can't have blockquotes within an ordered list without restarting the count.
Rewrote fir filters with vanilla ram and rom, tweaked others toward compiling.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	fpga/hdl/parallella-I/parallella_z7_top.v