See #1286

Why:

 * During backup process Termux is being killed in most cases.
 * Backup data is limited to 25 MB.
 * Backup may not be performed/updated in certain cases.

The scrolling region set by DECSTBM should not affect the
Cursor Down (CUD) and Cursor Up (CUU) escape sequences.

Fixes #1340.

Remove tests that asserted that Cursor Down (CUD) and Cursor Up (CUU)
escape sequences were affected by the scrolling region set by DECSTBM.

This was incorrect and recently fixed:
#1340

Related issue: #905

Do not disturb mode is now handled only for SDKs pre-28. Extra keys will
not vibrate only when total silence mode is used.

We are targting on API 24, so conditionals for Android 5/6 compatibillity
are useless now.

…state

Fixes utility 'reset' not being able to clear scrollback buffer.

update WcWidth.java, add note about c version

…ng session

See #1713.

See #1670.

String.join() is available only on Android API 26+ but our current
minimal is 24.

See #1670.

A basic implementation of APK-based package management.
Can install/uninstall Termux packages or output a list of installed ones into Android log.

* Improved notification management.
* Implemented downloading from the Google Play Store.

staging.termux-mirror.ml will be down and shouldn't be used.

* Changed the hardcoded cache directory to the android alternative (pointing to /data/user/0 which is a symlink to /data/data).
* Implemented the transparent activity mechanism for downloading multiple apps through the Play Store (which just works as if the intent was added to the back-stack)
* Now we check deliberately check for source (external for ext. repo and play-store for the Play Store).
* Fixed a few bugs.

…re versions

On Android 11 we need MANAGE_EXTERNAL_STORAGE to access files without
restrictions on shared storage.

Android 10 we have to opt-out from scoped storage and use WRITE_EXTERNAL_STORAGE.

…GE granted