two android changes and an a reminder

[pazos]

Changes - available since v2019.12-13-g59deaf6

Both have to deal with files and both are useful on recent android versions.If your device runs 4.0 - 4.4 you probably won't need any of them.

1. you can view content from other applications
   
   KOReader is now available in the "app chooser" dialog for supported documents
   
   This opens the file **without** making a copy. It was tested with SolidExplorer, RootExplorer and Simple Tools FM. It should work with other filemanagers too.
   
   When opening files where KOReader can read and write:
   
   - The metadata of the document will be stored on document's path (under the folder $document.sdr)
   - You can move your files without loosing annotations, highlights, etc as long as you move your document and your "sidecard" folder
   
   When opening files where KOReader can read only:
   - The metadata will be stored on a common path.
   - You'll loose data if you move the file (outside koreader, I mean. You cannot inside). Well, is not lost but you'll need to fix things manually because the metadata is stored based on the path, not based on a hash of the file.
   
   
2. you can import documents using the common Storage Access Framework. (requires android 4.4+)
   
   From the integrated file manager, using the "+" button and pressing "import files here".
   As the name states the will import the file to that specific path. So the workflow to import files is: navigate to destination path -> import files there.
   
   Nowadays this is only useful for certain kind of providers (apps like Termux, OTG storage,?) but on -future- api3?+ this will be the only way to "explore" the filesystem.
   Until then use it as a fallback of the first feature.

Reminder

KOReader ask for write permissions on primary storage.
Normally the primary storage is the phone/tablet/ereader internal partition but the user can change this and setup a sdcard instead
Outside the primary storage we cannot write