Implement basic modes

Add their PictureBoxes, a Integer variable which keeps track in which
mode we are, and basic switching between modes.
Implement playing beats from modes

This is experimental until there's a way to load beats into modes'
Launchpad Buttons.
Implement loading beats

Beats can now be properly loaded (one by one)! Bulk Open and other
opening functions will work only for the first mode (on key D5).
Add WMP events to 2nd mode

This involves showing colors, but still not changing them.
Add WMP events to 3rd mode
Add WMP events to 4th mode
Different colors for each mode
Behaviours for each mode
Form3.vb Bugfix
Bulk Open with modes
Fix Bulk Open with modes
Exporting Presets with modes
Importing Presets with modes
Merge pull request #2 from dominik-matijaca/modes

Modes