precursors.md: in Oberon add links to Wirth's FPGA CPU
 in BauHaus fix link to main story at lispm.de
utilities.md: add Leo editor/outline/pin,
 in myHDL fix broken links and add link to myCPU
language.md: in PyPy add link to its bytecode interpreter doc
 in Byterun add link to related blog series on Python bytecode etc.
 add pyCPU bytecode interpreter for FPGA