* Added continuous integration
* Formatting, documentation, static analysis
* Compilation and testing with GCC and Clang on Linux with FFTW3 and MPICH.
* Refactored trace metadata storage classes. Now called `Trace_metadata`.
* Refactored low-level I/O class, now called `Binary_file`, with an MPI implementation called `MPI_Binary_file`.
* Refactored file reader and writer interfaces, removing the need for an object layer, making specialization for new seismic file types more obvious.
* Renamed namespaces to use all lower-case.
* Added a number of static analysis checks, including the cases of variables and functions.