typo fixes
In comments and i18n strings only (i.e. not in the names of variable,
where there are still typos).
- "formating" -> "formatting"
- "fullfill" -> "fulfill"
- "occured" -> "occurred"
- "pathes" -> "paths"
- "proccess" -> "process"
- "refrence" -> "reference"
- "requiered" -> "required"
- "unknow" -> "unknown"