TextLayer selection coloring improvement for overlap.

As a consequence of merging #5221 it is more likely to have multiple
overlapping selection divs inside the text layer. Because each individual
element gets the selection style applied, the 30%opacity stacks, making a
60% bar visible where the overlap happens.

As proposed by @rocallahan, this can be fixed by making the selection
style solid and setting opacity for the overall layer.

I assume also that this should make the work for the renderer easier, but
was unable to bench it.
Fixes names collisions in content.js
Builds distribution package for npm and bower.
Improve the getData unit test

As a follow-up to PR #4795, this patch improves the `getData` unit test to ensure that the returned data is of the expected type and of the correct length.
Merge pull request #5327 from yurydelendik/dist

Builds distribution package for npm and bower.
Merge pull request #5330 from Snuffleupagus/better-getData-unittest

Improve the getData unit test
Merge pull request #5314 from yurydelendik/issue5313

Fixes names collisions in content.js
Merge pull request #5282 from CodingFabian/nicer-overlapping-text-selection

TextLayer selection coloring improvement for overlap.
ChunkedStream with chunked memory support