This commit drops the 'ua_' prefix and changes the public includes
to the form `#include <open62541/server.h>` instead of the old
`#include <ua_server.h>`
Make use of EXIT_SUCCESS and EXIT_FAILURE from stdlib.h.
The previous approach of returning a value from UA_StatusCode
was often broken as an exit code can (portably) only be between 0 and 125.
The LocaleIds was formatted with an underscore as separator between
the language and region. According to the OPC UA specification the
language and the region shall be separated by a hyphen.
Also removed LocaleId in those cases where a specific language is not
addressed, i.e. when presenting a type name.