Revert "update firmware.bin and checksum"

This reverts commit 905a63978dd5ab2c3ff4244b5a3714f46a6859b0.
Revert "Ignore qtcreator project files"

This reverts commit 5271ddf5a270e8b17151dad38075376973f32438.
Revert "DHCP hostname support (option 12)"

This reverts commit ff891972ee7cde4b3c51b30b8faca540313cce49.