Release version 0.8.0

New features:

• Added new API endpoints for Changeset create/update/close (#206)
• New handler for /*/relations and node/*/ways (#166)

Bug fixes:

• Fix compilation issues for libpqxx 6.x (#200)
• Use boost::spirit::standard instead of boost::spirit::ascii to avoid assertions failures in param list parsing
• Prepend HTTP 412 error text w/ Precondition failed: for Rails port compatibility (#211)
• JSON format fixes (#218, #219)
• Vagrant: dist update fix (#216), use Bionic (#217)

Refactoring:

• Improved XML parsing, using parts of libxml++ (#209)
• Replace boost regex by c++11 std (#205)
• Refactoring transaction handling (#204)
• Simplify changeset cache sql (#202)
• Application router HTTP method handling

Breaking changes:

• Remove write api backend (#198)
• Remove pgsnapshot backend and all related special case logic (#196)