Added optional property to disable default animation logics

Note: adding <style> block to head can be very slow on Android (S3 v4.3) due to rearranging heavy CSS structure. This option allows to rely on static CSS styles based on class names instead.
Merge branch 'refs/heads/optional-use-default-animation' into add-fasttap

Conflicts:
	build/pikabu.min.js
	src/pikabu.js