Web GUI now uses Chromium Embedded Framework.

Mostly works. On Linux there is annoying bug that causes X errors due to
excess mouse movements. It might be tied to GTK+ version.

Also inadvertently fixes upstream issue #80.
Updated the README.

* New asset package.
* Typo.
Fixed some obnoxious errors.
Adjusted CMakeLists and added options to build as a library
Added symbols to be Exported, moved ctors to cpp files to avoid exporting getFactoryFunctions
Added option to build with static GLEW defaults to not, fixed formatting in FindGLFW3
Make sharedlib + exe the defaults
Adjusted travis.yml glfw settings
Adjusted output names (libSigma instead of liblibSigma)
Made the output directories for library and executable the same
Changed output names, Sigma.dll/.lib Sigma_static.lib on Windows, libSigma.so/.a on Linux
Fix audio not playing beyond 4 seconds on OS X.

The OS X implementation of alGetSourcei alway returns 0 for AL_BUFFER
if the input source is streaming.
Added a catch in InjectMouseMove to prevent a crash if an event is sent before browsetHost is initialized
Test adding CEF to travis.yml
Finallized changes to travis.yml
Changes to Sigma build flags for CEF
Added back the CEF wrapper build
Changed link dir for CEF.
Added a Logger to Sigma, that can outputs to std::cout or any other output stream. Also there a little addition in CMakeFileLists.txt to allow to generate a executable for each one .cpp file in src/tests/
Fix typo