Added:
 History completion
 Command background color
 import-out-of-sync checker
Forgotten files
Import and Export now also work for REPLCommands
Refactored XML files
Refactored output mechanisms
Command can now be cancelled by pressing ESC
Fixed some minor bugs
Fixed 2 minor bugs:
 - Import was not properly removed
 - Linepainter returned an exception when the screen was cleared.
Fixed 2 bugs:
 - History completion disabled if line consists of multiple lines, so that tab can be used for indentation
 - Command background lines were removed after selection of text.
Added output folding