Configure the selector of courseware by platforms.
Use the selector configured by the platform.
Merge pull request #87 from shk3/aria-integrated-by-platforms

Configure the Selector for Courseware List by Platform
Fix #92 Updated subtitle URL string after edx changes.

the request URL is composed of information given in the page objects
data-transcript-translation-url + videoId + data-transcript-language,
e.g.
https://courses.edx.org/courses/BerkeleyX/CS184.1x/2012_Fall/xblock/i4x:;_;_BerkeleyX;_CS184.1x;_video;_L1V3_Online_Graphics_Overview_History/handler/transcript/translation?videoId=HD_59nFVzkU&language=en
Merge pull request #96 from iemejia/shk3

Fix #92 Updated subtitle URL string after edx changes.
Merge branch 'master' into console_encoding again.