- new API call: efficient distance table computation
- use 100 locations at max for dist table (for now)
- JSON output generation through a dedicated JSON container
- deactivate LTO on debug build
- fix performance regression in preprocessing
- use static assertions for better source code correctness
- add some static asserts to guard against memory usage regressions
- do less work when compressing geometries
- move most geometric calculations to float
- replace boost::unordered_map, move hash function for pairs into its own header
- refactor route name extraction into its own class, fix name extraction
- further includes untangling
- introduce range based for loops to traverse graphs
- further boost by STL replacements
- use lookup tables from some trigonometry functions
- fix compile regression in debug build
- further code improvements and bug fixes

Please not the following (minor) breaking changes:

- the JSON formatted output now omits empty, i.e. unused fields
- the response file names are now response.js(on) or route.gpx