Renamed ismounting, setmounting, @mount2

To avoid ambiguity:
- The script command ismounting is now hascashmount
- The script command setmounting is now setcashmount
- The at-command @mount2 is now @cashmount

Signed-off-by: Haru <haru@dotalux.com>
Re-commit of 4ac673941714032ada6d26fb60936ec510bbe496 (part 3)

    Some Quality of Life Changes

- setdragon, setmadogear and setriding deprecated; use setmount instead.
- checkdragon, checkmadogear, checkriding deprecated; use checkmount
  instead.

Signed-off-by: Haru <haru@dotalux.com>