Sync logging, Thumb-respeaking gesture handling
Sync logging modified, Thumb-respeaking gesture bug fixed, original rewind after each respeaking is recorded
Pruning unnecessary codes
Minor changes(default-rewind changes to 0.5sec, sync with aikuma folder)
Minor changes(rewind-amount is forced to be number, documentation change)
Merge pull request #273 from lisaslyis/master

This request resolves #43, resolves #122, resolves #216, resolves #258.