[Minotaur] Minotaur release 0.3

[Ashutosh Mahajan]

Dear all 

We are happy to announce a new release of Minotaur, a software for
mixed-integer nonlinear optimization. Source code is available on GitHub
(https://github.com/minotaur-solver/minotaur) along with some documentation
and references. We will try to make binaries available soon, and also install
them in our department machines. We have many things to improve upon. If you
use it for any problems (just for experimenting, or fun or any other use), let
us know. Any inputs and help are most welcome.

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Release Notes for Minotaur v0.3
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New features
- A new shared-memory parallel version of Quesada-Grosmann (mqgpar) with extra
  linearization schemes
- A new solver, mglob for global optimization of MIQCQPs
- New solvers moa (outer-approximation) and mlstoa (lazy cuts based
  single-tree outer-approximation) for convex MINLP using Cplex MILP solver.

Libraries, binaries and interfaces
- merged multiple source and interface related libraries into a single
  (libminotaur) library
- nl files can be written
- mps files (linear only) can be read
- C-interface with Cplex's LP and MILP solvers (CplexEngine)

Improvements and bug fixes
- several bugs fixed in the nonlinear branch-and-bound (mbnb) and
  Quesada-Grossmann (mqg) solvers
- removed all boost shared pointers; using normal pointers now
- website moved to https://minotaur-solver.github.io/

Source code
- moved the subdirectory algorithms in src/ to solvers
- consolidated interfaces to third-party software like ASL,
  LP, MILP and NLP subsolvers in src/interfaces

Third-party software
- upgraded third-party software and their dependencies

Regards
Meenarli Sharma, Prashant Palkar, Mustafa Vora, Ashutosh Mahajan and others
from team Minotaur