[api-minor] Change EventBus.dispatch to only support *one* data-argument

[Snuffleupagus]

This is consistent with how the EventBus has always been used internally in the viewer, and allows a slight simplification of the relevant code.

[Snuffleupagus]

/botio unittest

[pdfjsbot]

From: Bot.io (Linux m4)

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Received

Command cmd_unittest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.241.84.105:8877/28371b6e3f6e2d7/output.txt

[pdfjsbot]

From: Bot.io (Windows)

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Received

Command cmd_unittest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.193.163.58:8877/79f3cb296aa56db/output.txt

[pdfjsbot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/28371b6e3f6e2d7/output.txt

Total script time: 2.97 mins

• Unit Tests: Passed

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://54.193.163.58:8877/79f3cb296aa56db/output.txt

Total script time: 5.77 mins

• Unit Tests: Passed

[Snuffleupagus]

/botio integrationtest

[pdfjsbot]

From: Bot.io (Linux m4)

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Received

Command cmd_integrationtest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.241.84.105:8877/d9e19f2a47cc1ef/output.txt

[pdfjsbot]

From: Bot.io (Windows)

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Received

Command cmd_integrationtest from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.193.163.58:8877/1b5fbdf8f35b8dd/output.txt

[pdfjsbot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/d9e19f2a47cc1ef/output.txt

Total script time: 3.75 mins

• Integration Tests: Passed

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://54.193.163.58:8877/1b5fbdf8f35b8dd/output.txt

Total script time: 7.61 mins

• Integration Tests: Passed

[timvandermeij]

Thank you for simplifying this code!