Fix code formatting for including headers

NLopt is used as a git submodule, this allows not to confuse options of the parent project.

Install PDB file with debug information when using Visual Studio

Test shared libs on appveyor

Add namespace for CMake targets and add install include directories to target properties

Fix get|set lower|upper bounds methods warnings

Update doc

Fix all uninitialized variable warnings

Enhance testopt following #85

Use swig_add_library with cmake 3.8

Every variables that yields a -Wmaybe-uninitialized gcc warning is set to 0

Fixes #133

Prefer target_include_directories in CMake build script

* fix for #51

This pragma fixes a known problem compiling with VS2013 or VS2015 in Release.
See issue #51 for more info.

* The fix fod Visual Studio starts from version 2013 onwards.

This has not been fixed for VS2015, so we keep the macro guard open for future versions of VS.
The vectorization of this loop is not that important anyways.
See #51.

* added mkdocs-style documentation tree in doc

* added documentation tree converted from ab-initio wiki pages

Fixing Integer Overflow in nlopt_srand_time