unit tests

[ngokevin]

Unit test recorders and players.

Actual code changes include:

• Fixes to event playing due to wrong variable names used.
• Handle axismove event, which has different event details than the buttons.
• Use camera-set-active (camera set) rather than camera-ready (camera created).

[dmarcos]

It's nice to have the infrastructure in place but I would not put too much effort now until the API consolidates a bit

[ngokevin]

Tests will let you progress the API without worry about breaking functionality.

[ngokevin]

Rebased.

[dmarcos]

Merging. but tests can slow you down without knowing what functionality you want yet. unit tests are better introduced when API starts to cristalize