Add possibility to organize files in bundle
Add WAVE reader
Add pitch to attack command

Examples:
a:c4+50; +50 cents
a:c3-25; -25 cents
a:c5;    no pitch
Rearrange values to prevent integer overflow
Update submodule which fixes error
Generate error on invalid sequence
Keep arpeggio after release
Fix commands in example files
Fix frame shift
Update copyright year
Fix warnings
Add check if file exists
Add string buffer check
Update submodule
Bump version to 0.4