version 0.1.0

• propagate internal errors to caller

• LT_VERSION 1:0:0

  • extend the API for the error propagation

    • add tagsGetErrno function
    • add tagErrno eum type

  • break the API

    • rename sortType to tagSortType for avoiding name conflictions
      However, sortType is still defined as a macro.
      See readtags.h.