new top-level fpgabuild.sh and script updates in the style of nanosoc

..._demo/systems/cortex_m0_mcu/fpga_imp/build_fpga_clean.scr

...port/pynq_z2/jupyter_notebooks/soclabs/driver/uartlite.py

...ynq_z2/jupyter_notebooks/soclabs/soclabs_cm0sdk_mcu.ipynb

.../pynq_zcu104/jupyter_notebooks/soclabs/driver/uartlite.py

...zcu104/jupyter_notebooks/soclabs/soclabs_cm0sdk_mcu.ipynb

...tems/cortex_m0_mcu/fpga_imp/scripts/build_mcu_fpga_ip.tcl

...cortex_m0_mcu/fpga_imp/scripts/build_mcu_fpga_pynq_z2.tcl

...ex_m0_mcu/fpga_imp/scripts/build_mcu_fpga_pynq_zcu104.tcl

fpgabuild.sh