add documentation to crate spawner / dropper
purge the classic mods from the source tree

they are unmaintained and no one wants to play them
added make version command

to quickly set the mods version to the git tag
or git-$hash if we are on a development version
Merge pull request #3120 from Mailaender/classic-removal

Goodbye classic mods
don't hard-code smokey.shp
fix crash in d2k - the smoke sprite is currently undefined

it used an RA one before, was hidden in the source code
Merge pull request #3136 from Mailaender/smokey

Don't crash d2k when shooting at aircraft and don't hard-code the sprite in smoke trails.
fix survival01 crash on start
Merge pull request #3138 from chrisforbes/survival-fix

fix survival01 crash on start, closes #3131
Tanks' ROF increased
Increased ROF of tanks. The guns of Light & Medium Tanks are a bit weak
relative to their role as tanks. They do less damage than bike rockets,
and do less damage against light vehicles than even the hum-vee. Changing
ROF should mitigate this a bit, even though their gun is still not that
powerful (e.g. compared to stealth tank, and even flame tank matched light
tank). The fact that their rivals are often moving fasts also complicates
the slower ROF.

The same proportion of damage was kept between light & medium tanks.
Mammoth Tank was left unchanged.
Merge pull request #3140 from psydev/bleed

Tanks' ROF increased
Added missing target line for DemoAttack

fixes #3122
Remove alt key modifier from build palette hotkeys. Changed some hotkeys for units and buildings.
Change soviet buildings BuildPaletteOrder to be consistent with allied buildings
Move flamethrower and shock trooper BuildPaletteOrder values around
Merge pull request #3147 from Mailaender/demo-flash

Added missing target line for DemoAttack
Merge pull request #3150 from cjshmyr/hotkey

Hotkey changes
Fix assign teams dropdown position.
Remove ICMP based pinger
Reimplement pinging via the orders channel.