Update to latest upstream 1.3.13
    
    - improvements in the latex.txt table:
      \langle and \rangle were previously U+2329, U+232A from Miscellaneous Technical.
      Changing them to U+27E8, U+27E9 from Miscellaneous Mathematical Symbols-A makes
      more sense and lets us also add the double angle brackets U+27EA, U+27EB.
      Patch by Jonathan Chan.
      (Resolves: https://github.com/moebiuscurve/ibus-table-others/pull/24)