* add escapecss filter
this filter would allow creating valid css classes from titles containing special characters
we assign a class to an element using `encodeuricomponent[]` so that the class name is encoded
in a stylesheet we create the classname by `<title>escapecss[]` which applies the uri encoding and escapes characters that need to be escaped
* Update encodings.js
* refactor tagToCssSelector, add escapeCssSelector
* use escapeCssSelector
* escape using CSS.escape if it's available
* Update encodings.js
* revert factoring out escapeCssSelector