Reverse T(P,H) Patch Release

What's Changed

• Add postgresql wrapper by @mmouterde in #31
• Reverse T(P,H) patch by @henningjp in #36
  • Updated Mathcad wrapper README to reflect Prime and Legacy version status
  • Bumped version to 2.1.3
  • Updated IAPWS Units comments for clarity in header file

New Contributors

• @mmouterde made their first contribution in #31

Full Changelog: v2.1.2...v2.1.3

Improved CMake configuration

• Structured the processing of CMake options
• Cleaned CMake command spelling
• Added the version number to CMake
• Fixed the CMake command in the docs
• Added a link to the wrapper README
• Added new modules for header file and CMake

Install targets fixed includes

• added algorithm include
• bumped version number
• turned build switches into options
• added a standard interface library target IF97_CMAKE_MODULE
• minor adjustment in documentation

Optimizations and Patches

• Patch std::vector operations for MSVC 2008 compatibility
• CMake build script update to support Mathcad wrappers
• Patch saturation curve logic in Saturation functions
• Function rho_pX patch for PS and PH input pairs
• General speed optimizations
• Implement IAPWS_UNITS compiler switch for verification against IAPWS docs

Contributors: henningjp, rafuck