Import library menu is now scrollable.

Fixes #1543
Scrollable menus can now be scrolled with the mouse wheel
Changed 'Copy error' button: bigger font, shorter text
Slightly reorganized reports from 'Copy error' button
Fixed robot libraries and examples for unified Arduino core
Fixed preference parsing (hashtable was concurrently updated while iterating on it).
Merged robot core
Updated robot examples and libraries

Merge branch 'master' into ide-1.5.x