Update Match sha1

    Functionality updates/fixes

    * Use subarrays in all cases of matching arrays,
      except when when selecting a single index
    * Generate default result when not using =>
      * var1 when the pattern contains 1 capture variable
      * (var1, var2, ...) when the match expression contains
        multiple capture variables
      * true otherwise
    * Also allow captured variables to "escape" when not using :(=>)
    * Change matrix tests to not use :(=>)
    * Update README.md to match changes
    * Other minor efficiency updates/bugfixes