Removed comments around block in object.c
Add error identification

This patch introduces a error member in the deserializer state type to
handle certain parsing errors, such as internal ones (for example
-ENOMEM) and YAJL parsing errors, to be able to tell the plugin what
happened.
Add error identification handling in yajl_null_cb()
Add error identification handling in yajl_boolean_cb()
Add error identification handling in yajl_integer_cb()
Add error identification handling in yajl_string_cb()
Add error identification handling in yajl_map_key_cb()
Added get_mouse_surface to global context
Added get_keyboard_surface to global context
Fix initialization of EGL buffers
Fix deinitialization of EGL buffers
Merge pull request #496 from neithernut/fix-egl_buffer

Fix egl buffer (de)initialization
Fix refcounting in object

This commit also fixes unref().
Previously, we had a lock for refcounting but didn't use it _at all_.
This commit introduces proper recount-locking and thus fixes a _lot_ of
potential issues.
Add log when initializing deserializer
Add log when initializing deserializer internal state
Add logs to deserialize callback
Add log context for deserializer callbacks
Add stack based initialization for EGL buffers
Add log for logging what gets parsed atm
Add explanation logs for yajl_null_cb()