Convert arrays to hashes

Stop searching in arrays.
Use less bytes for values
Fix tests for the progress element

The progress element has no sense without value.
Fix tests for the range element

The jsdom library has a bug and does not set a default value for
the range element.
Migrate to accessibility tree

Increase performance on complex trees.

The nodes of accessibility tree are no longer created on demand.
Reusing nodes should speed up processing.

Storing data on the nodes allows to skip accessing DOM tree, thus
increasing performance even more.
Fix using of global object
Stop inserting nodes to DOM tree

No longer necessary.
Merge branch 'performance'

Migrate to accessibility tree to increase performance on complex data.