Makes rank chevron palette customizable.

Adds levelup crate-effect and art.
Make Wall its own TargetType

Going to make some units (machineguns, etc.) unable to fire at walls.
Certain units can no longer target walls

Units which cannot target walls (sandbags, chain-link fence or concrete) any longer:
Minigunner
Flamethrower
Hum-vee/Nod Buggy 
Flame Tank (can still run over sand bags and chain-link fences)
Civilian
[sniper--already so]
Remove unused and obsolete Cached.cs

This was similar to Lazy<T>
Remove custom Stopwatch wrapper

Remove the redirection (that doesn't offer any new functionality)
and replace it with the familiar System.Diagnostics.Stopwatch.
Replace (and remove) custom Set<T> with HashSet<T>
TD Blossom Trees now emit tiberium from base.

Dimension set to 1x1, art position fixed via sequence Offsets.
Adds die-crushed sequence to Shock Trooper.
Adds work-in-progress test map to TS mod.

Creeps-owned units and buildings can be used to test rank signs etc.
Merge pull request #5199 from reaperrr/shok-fix

Closes #5195
Merge pull request #5185 from reaperrr/rank-palette

Makes rank chevron palette customizable
Merge pull request #5198 from reaperrr/tibtree-fix

Closes #3107
Merge pull request #5194 from psydev/patch-8

Certain units can no longer target walls
Merge pull request #5197 from pavlos256/minor-cleanup

Minor cleanup
Add UseInfantryDeath option to RenderInfantry trait.

This allows the use of RenderInfantry for units that do not have a Die voice or die sequences.

Additionally fixed Wolverine stand and shoot sequences.
Fixes palette of all TS weapons that don't use the effect palette.
Merge pull request #5206 from reaperrr/ts-mechfix1

Added UseInfantryDeath option to RenderInfantry trait
Merge pull request #5207 from reaperrr/ts-weapon-pal-fix1

Fixed palette of all TS weapons that don't use the effect palette
Un-hardcodes pip/tag/group palettes.

-Palette for decorations can now be defined under SelectionDecorations trait.
-Adds pip types Ammo and AmmoEmpty.
-LimitedAmmo PipTypes are now customizable.
-Adds art, sequences and rules entries for TS mod decorations that were missing/using a wrong palette.
-Adds PrimaryBuilding trait to TS weapon factories and helipads.
Makes CrateEffect color palette customizable.

CrateAction can now define a custom Palette, levelup effect of GainsExperience uses ChevronPalette.