Idea: KoReader Plugin Auto-Update

[tku137]

Working on #84 I had the idea of an auto-update mechanism in the koreader plugin.

From a quick inspection, these would probably be the major tasks:

• /version api endpoint
• update_check.lua plugin module
• CRITICAL: can a plugin overwrite its own files?
• if possible, restart koreader right away or at least display such a hint

Theoretically, since KoReader is lua based, files are in-memory, so overwriting does not interfere and after a reboot, the plugin files are loaded again.

Things to research/test:

• How do other plugins do auto update stuff? (I saw this somewhere)
• zip extraction in KoReader possible?
• overwriting files + restart = auto-updated plugin?