Not all weapon behaviors are visible in the physics editor

[Tacticus359]

The "horizontal amplitude" option is not visible. Not sure if there are others in addition to that.

[treellama]

horizontal_amplitude is used by the engine, but always set to 0 in the definitions and editors. Its use seems to differ from bob_amplitude in a significant way, too, so I don't know that there is much point making it editable.

The other field is powerup_ticks, which is unused.