Reduce the size of saved and exported builds by encoding the settings instead of compressing them.

[Mijago]

For this, remove the Dependency on the lzip library and encode the data 'manually'.

My dream is that we encode the whole config in a short string which can be shared. Best: ASCII only, no fancy Unicode.

Problems I see:

• Ignored items (might not be an issue if we move them to the app settings referenced in #123)