exec_finish_install will run all executable scripts in the
finish_install dir in turn.
Add support to ext4 in mount_partition.sh
move auto_install.py and state_grid.py to text dir
modified: operation/exec_finish_install.sh
new file: operation/finish_install/95state_grid_custom.py
modified: operation/finish_install/99finish_install.sh
new file: operation/finish_install/exec_post_add.sh
modified: operation/install.txt
modified: operation/mount_partition.sh
renamed: AutoInstall/auto_install.py -> text/auto_install.py
renamed: StateGrid/state_grid.py -> text/state_grid.py
