Qcserenity

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- Various bug fixes and unit tests
- Tracking warnings in separate file (David Schnieders)
- Added HDF5 support for energies (David Schnieders)
- Rewrote contribution guide (Jan Unsleber)
- Added semi-numerical Hessian and frequency analysis (Kevin Klahr)
- Integrated freeze-and-thaw optimization into optimization task (Kevin Klahr)

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- Clean GCC-5 warnings (Jan Unsleber)
- Add basis and .h5 test files to build artifacts (Jan Unsleber)
- Update to new repository location (Jan Unsleber)
- Added support for a .pdf manual to CI (Jan Unsleber)
- Added license to each source file (Jan Unsleber)
- Added manual draft (Jan Unsleber)

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(a short list of initial features)

Electronic Structure Methods

- Hartree-Fock (incl. gradients)
- Density Functional Theory (incl. gradients and RI)
- R-MP2/R-CCSD/R-CCSD(T) (only small systems)

Initial Guesses

- hCore Guess (zero electron density)
- Extended Hueckel Guess
- Atomic Density Guess (simple version, but works well)

Embedding Techniques

- FDE (incl. gradients and RI-J)
- Freeze and Thaw (incl. geo. opt.)
- Potential Reconstruction
- Projection Based Embedding (restricted/no basis set truncation)

Further Tools

- Mulliken Population Analysis
- Orbital Localizations (PM, FB, IBO, EM)
- Output of electron density, MOs and other data in cube format

Technical

- libint2 will be pre-generated and shipped with Serenity
- libint 2.3.0-beta3 is linked