adapt decrypt all and restore/delete key backups to the new folder structure for encryption key introduced with OC8

It's better to encode the string to prevent possible (yet unknown) bugs in combination with PHP's type juggling.

Previously the boolean statements evaluated to either an empty string (false) or a not empty one (true, then it was 1). Not it always evaluates to false or true.

This also removes a stray - that was not intended there but shouldn't have produced any bugs. Just to increase readability.

Thanks @nickvergessen for spotting.

Addresses https://github.com/owncloud/core/pull/13235/files#r22852319

The internal path was matched without the last "/" which caused
"files_trashbin" to also match when the internal path was "files".

This adds the missing slash for the comparison.

Apparently `normalizer_normalize` is not verifying itself whether the string needs to be converted or not. Or does it at least not very performantly.

This simple change leads to a 4% performance gain on the processing of normalizeUnicode. Since this method is called quite often (i.e. for every file path) this has actually a measurable impact. For examples searches are now 200ms faster on my machine. Still not perfect but way to go.

Part of https://github.com/owncloud/core/issues/13221

Isset is a native language construct and thus A LOT faster than using strlen()

On my local machine this leads to a 1s performance gain for about 1 million paths. Considering that this function will be called a lot for every file operation this makes a noticable difference.

`normalizePath` is a rather expensive operation and called multiple times for a single path for every file related operation.

In my development installation with about 9GB of data and 60k files this leads to a performance boost of 24% - in seconds that are 1.86s (!) - for simple searches. With more files the impact will be even more noticeable. Obviously this affects every operation that has in any regard something to do with using OC\Files\Filesystem.

Part of https://github.com/owncloud/core/issues/13221

The check for invalid paths is actually over-complicated and performed twice resulting in a performance penalty. Additionally, I decided to add unit-tests to that function.

Part of https://github.com/owncloud/core/issues/13221

The current behaviour of the authenticion logic in base.php prevents REST APIs in ownCloud applications to work.

Because `!self::$CLI` is usually always a true statement the previously above block was entered which returned, thus the authentication logic for this part does not trigger in.

This can be reproduced by installing apps such as the News app and issuing the following command:

`curl -u admin:admin http://localhost/index.php/apps/news/api/v1-2/feeds`

The following parts needs to get throughly tested:

- [ ] OCS
- [ ] remote.php's DAV features
- [ ] Regular login features

This bug affects master and stable7. I'd propose that we merge this for 8.0 since this has the potential to break every component that relies on Basic Auth features. A backport would also be very nice.

Remark to myself: We really need to move out the authentication code for 8.1 out of base.php - I already have a local branch that does that somewhere which I will get in shape for 8.1... - This untested code is a night-mare.

Fixes itself.

Otherwise every time the AppStore was opened a lot of connections to the AppStore server were made which resulted in a terrible performance.

This changeset will cache the response for a sensible time so that only the first request will be somewhat slow.

Performance changes:
- Loading a category took previously more than 3 seconds on my machine. Now for every follow-up request it takes less than 200ms, resulting in a performance gain of 1950%
- Loading the category list took previously about 750ms - now it takes 154ms, a total performance gain of 395%

It's slow, this makes it fast!

`$this->info` can very well contain an empty array or possibly other values. This means that when this code path is called a PHP Fatal error might get thrown which is not what we want.

Currently if a user does not replace the .htaccess file with the new update this can lead to serious problems in case Apache is used as webserver.

This commit adds the version to the .htaccess file and the update routine fails in case not the newest version is specified in there. This obviously means that every release has to update the version specified in .htaccess as well. But I see no better solution for it.

Conflicts:
	lib/private/updater.php

check for working htaccess will result in a dead lock because the server is blocking the request to itself - fixes #13153