Added ws_wayland_buffer_release
Added frame callback implementation to support changing buffers
Added null check against surface from wayland
Removed the + 8 modifier from keycodes

This is something the client should do it seems. `weston-terminal` at least
seems to expect non offsetted key events... For the moment we have no choice but
to trust their code.
Removed double keyboard handle
Added modifiers to keyboard
Remove trailing whitespace(s) in src/command/statement.h
Remove trailing whitespace(s) in src/command/string.c
Remove trailing whitespace(s) in src/connection/config_file.h
Remove trailing whitespace(s) in src/connection/connector.h
Remove trailing whitespace(s) in src/input/hotkey_dag.c
Remove trailing whitespace(s) in src/objects/named.c
Remove trailing whitespace(s) in src/serialize/serializer.c
Remove trailing whitespace(s) in src/values/string.c
Remove trailing whitespace(s) in src/values/string.h
Remove trailing whitespace(s) in tests/check/input/input_tests.c
Merge pull request #473 from manuelmessner/remove-trailing_whitespaces

Remove trailing whitespaces
Merge pull request #498 from TheNeikos/fix-wayland_client_interaction

Fix wayland client interaction
Added ws_surface_set_role
Added role setting to pointer and shell