doc: use drystal.colors in basics.lua
doc: update spritesheet.png
doc: add documentation for Audio module
doc: add documentation for the Event module
doc: use appropriate rst tags
event: replace resize_event by page_resize
doc: add documentation for Timer and new_timer
audio: pitch should be strictly positive
doc: some precisions (buffer type, new_shape optional arguments)
lua: fix parsing error not being printed
add NEWS
tests: fix buffer.lua and filter.lua
Release version 1.1

Update version number, add release date for Classy Sea and the link to the demos repository