Add "fear" effect

causes enemies to flee
Move damage and absorb calculations to StatBlock

Fixes #472
MenuManager: Remove unused variable declaration
MenuActionBar: Remove unused parameters.
Fileparser: init current_index in constructor
WidgetScrollBox: Remove unused function removeChildWidget
WidgetTabControl: Remove unused function getTabsAmount
MapCollision: Remove unused function is_facing
MapCollision: Rename is_facing_wide to is_facing
Settings: explicit cast to int for unsigned in error message.
MenuTalker: move initialisation in constructor to init list
Merge pull request #645 from RyanDansie/fear_effect

Add a "fear" effect
Inputstate: Move variable declarations to smaller scope
Merge pull request #654 from dorkster/statblock

Move damage and absorb calculations to StatBlock
Merge remote-tracking branch 'mainline/master'
Merge pull request #659 from stefanbeller/master

Some code maintanence