1.4.2: Keypad directed validation

Implements:

• audibility, visibility and hasKeypad properties in the CSV;
• Automatic removal of the spaces in the CSV files, to avoid problems with spreadsheet editors;
• Keypad validation between each estimation, and submission at the end to pass to the next trial through participant input;
• Better default values/documentation about displacement-maps;
• Room material identifier in the operator interface;
• Emission color to the keypad so it's less dark in the shadows.

Fixes:

• Nullref on keypad interaction when a rating scale is displayed (should just prevent the interaction);
• Creation of eye-tracking data files even though the HMD isn't eye-tracking compatible;