CON-2283: do not use transparent color for infobox "show more" button
CON-2283: use getColorAlpha function from CON-2230
CON-2283: add unit tests for getColorAlpha
Merge branch 'dev' into CON-2283-infobox-colors
Merge pull request #5623 from Wikia/CON-2283-infobox-colors

CON-2283: do not use transparent color for infobox "show more" button