ticket #450: deleted misleading dismiss button when building apk

change-Id: I9e20aabd2493841ef865b93acd12f640aa128569
Fix typo in activity starter documentsation getType --> getDataString

Change-Id: I6a904c1ddf889f7e8f9a4d74d7e2dfbe4dd634b8
Only load assets into memory while sending them to the Companion.

This should reduce the javascript memory needed for projects with a
lot of assets.

Change-Id: I55eda14204f4273a5d6c93cd221c98fd39ef054c
Merge branch 'master' of https://github.com/mit-cml/appinventor-sources