-Fix (#169): some "empty" strings were not ignored when they should have been
Revert "-Fix: rewrote the movement code a bit again"

This reverts commit 32df764cb2a16d13d073ab0f05c0ce400f816285.
Revert "-Fix: I broke foot animation, oops (tnx wangds)"

This reverts commit 88af03ba0e49723cb7d060e3a553f5d3c8b0bc87.
Revert "-Fix: moving of units was kinda messy between gameSpeeds. This hopefully resolves it."

This reverts commit f125285489a34e967f3fc265308ea38d6d9dbbba.
-Fix: don't always round down (patch by wangds)
-Fix: airunits should be uneffected by gamespeed

By premature converting to and from gamespeeds, precision was lost,
resulting in different speeds for air units.
Also, it could adjust for speed twice, instead of once.

PS: this fixes sonic blasts reaching different distances on different
gamespeeds
-Fix: rounding lead to asymmetries when moving up/left vs down/right (based
-Codechange: movingSpeed is a factor, not an absolute value
-Fix: orientation calculation did not account for the cyclic nature
-Fix: track who deviated a unit (based on patch by AndO3131)
-Fix: set loading objects to 0 before using; avoids random memory
-Fix (#138): saboteurs don't always blow up when reaching their destination (patch by wangds)
-Fix: use Unit_Remove where a valid unit is being removed

Unit_Free forgets to update a few key elements, leaving dots on radar
and unbuildable tiles as result.
Tnx to wangds for noticing.
-Codechange: minor inconsistency in comments
-Fix (#161): a deviated unit was never attacked by turrets of his former ally
-Fix (#161): deviated units weren't seen as enemies by script

This also fixes that a deviated unit kept shooting its current target
-Codechange: name all FindTarget functions the same, also their local variables
-Codechange: don't do checks you check a few lines lower too, but in a child function
-Codechange: Unit_SetTarget(unit, 0) does not set the target to none (but does nothing instead)

Also, make deviate function consistent (reset target and destination in
both when you get deviated, as when you lose deviation)
-Codechange: use Unit_GetHouseID, just to be sure