Minor performance improvements.

Added safety check for pawns disappearing on load.

Add TargetValidatorDowned.

Fixed a bug that prevented setting essence-related options in the main menu.

Fixed an error when loading PsiTech in 1.1.
Fixed an issue that caused psychic apparel to not apply an offset to psychic sensitivity.

Essence tooltip string now states the correct value for essence loss.

Additional fixes for null reference issues.

Fix an issue that caused errors when a pawn without apparel was attacked.

Fix an issue with some files not being included in the update.

Some apparel can now be psychically enhanced at the psychic workbench after researching advanced psychic equipment, providing bonuses to psychic sensitivity (+50% for shell/outer layer apparel, +25% for overhead layer).