MeTA v2.0.1

Bug fixes

• Fix issue where metadata_parser would not consume spaces in string
  metadata fields. Thanks to hopsalot on the forum for the bug report!
• Fix build issue on OS X with Xcode 6.4 and clang related to their
  shipped version of string_view lacking a const to_string() method

Enhancements

• The ./profile executable ensures that the file exists before operating on
  it. Thanks to @domarps for the PR!
• Add a generic util::multiway_merge algorithm for performing the
  merge-step of an external memory merge sort.
• Build with the following Xcode versions on Travis CI:
  • Xcode 6.1 and OS X 10.9 (as before)
  • Xcode 6.4 and OS X 10.10 (new)
  • Xcode 7.1.1 and OS X 10.10 (new)
  • Xcode 7.2 and OS X 10.11 (new)