encoding edit in bookmark edit

[ghost]

Add encoding selection, compression level, and quality level in bookmark edit

[gujjwal00]

Some notes about this:

• IMO, exposing encoding selection to user is unnecessary. User probably have no idea what these cryptic names mean and which one is better. As LibVNCClient automatically chooses best encoding, is there any scenario where user might want to enable/disable some of them?
• Using a SeekBar instead of Spinner for quality/compression level might be better, as you can specify an integer range for it. This way you won't have to create multiple enums and do manual conversions.
• You could use the Quality Level to automatically calculate compression level (Low quality => High compression)