FIXED: Scrollbar locations

 * Partially fix panes' initial scrollbar locations
 * Fixed horizontal offset in map pane
CHANGED: Added defensive code

 * Prevent NPE if map.xml or texturepack.xml links to modpack which is not found from modpack list
Merge pull request #802 from jikuja/fixes_for_v1.4.0

Fixes for v1.4.0