Changes

add XercesValidator (#1257)

* add XercesValidator

* add validation tests

* add ssp schema

* use absolute path to schema location

* print full file path for error reporting

* add_compile_definitions "SCHEMA_ROOT"

* add schema/CMakeLists.txt

* add module whereami.c to get the executable path

* Trigger build

* fix docker image for alpine

* add linux-headers for alpine/Dockerfile

* use wai_getModulePath to locate the schema

* do not free the path

* add getExecutablePath()

* report as logWarning

* expected output

* update tests

* expected output

* fix typos

* set separate working directory for random failing tests