update schema annotations - WIP
add SchemaType annotation for @Schema types;
make SchemaEntry.path optional (one of path and tags is required)
schema: add support for @Description;
add method to compare Directions
move ContextUtil to sorce-api;
move new methods from Contexts to ContextUtil
replace System.out with slf4j
copy hasMarkedValue and getMarkedPaths from Contexts to ContextUtil
Merge branch 'schema' into v1.0-M3