Introduce a Buffer class and use it to replace custom API definitions for RenderCapture and xbmcvfs.File.
[cosmetic] remove commented out code.
The RenderCapture::getImage now returns a buffer that's ready to read from.
rename the current 'read' method to 'readBytes' and use it to implement a 'read' method that returns a string in order to preserve bw compatibility.
change the write back to a bool for bw compatiblity with the incorrect 12.0 api.
minor fix to the string length arithmetic.
Merge pull request #2359 from jimfcarroll/buffer

Addon binary reading and writing