Update - Robustness

This update makes Type Swap more forgiving towards some forms of unexpected input.

Thanks to all those that provided feedback during Talk & Play #40! This update consists completely of improvements based on your invaluable feedback.

The update contains the following improvements:

• Pressing space after the second word  of a swap is now ok. Previously it broke your streak and had to be deleted prior to entering words for the next swap.
• The tutorial now tries to help lost players by rewinding to previous steps in some cases.
• Pressing enter no longer selects the whole input, which lead to unwanted deletion upon next keypress .