partial implementation of daily update check
Merge branch 'apks' into apks-update

Conflicts:
	mobile/android/app/mobile.js
	mobile/android/modules/WebappManager.jsm
start reimplementing updates to be APK-centric
Merge branch 'apks' into apk-updates
readd files removed by merge
get outdated apps
getApkVersionNumbers working with initial 'check unknown sources' checkbox ui
disable synthapks by default; add option to enable feature
make formatting more consistent and conventional
build webapps/ unconditionally since we determine whether or not to use it at runtime
stub out functions we conditionally depend upon at runtime
do a bit more tidying
fix typo and simplify destructuring assignment of parameter properties
Revert "getApkVersionNumbers working with initial 'check unknown sources' checkbox ui"

This reverts commit 5c1b431f9b58406ef3e626f741bdf2962b19a804.
Merge branch 'apks' into apk-updates

Conflicts:
	mobile/android/app/mobile.js
	mobile/android/base/tests/testWebapp.java
	mobile/android/components/MobileComponents.manifest
	mobile/android/modules/WebappManager.jsm
implement APK version retrieval
add URL of fake update check service
remove test file (will reland in branch implementing test)
Merge branch 'apk-updates' into apk-test
add update test file