Gameplay changes + Fix + few new thing

Log :
- Fixed plant related timer wich was not according to delay between each
execution.
- Fixed an Antlion death message showed as an Headcrab death message.
- Fixed Antlion and headcrab being able to eat more than 1 food at once.
- Changed part of code that was quite useless.

- Changed death message.
- Changed how much leg are layed at once.
- Tree are growing faster.
- Increased max melon.
- Reduced health on spawn.
- Reduced max headcrab.

- Added random thing to egg time so the whole colonie does not lay egg
at once.
- Added health regeneration overtime.
- They can now eat while they are not too hungry. (still imposible if
<40)

- Removed Hp gained by eating.