Close #237: Replace setError with error events
* replace setError/getError with sendEvent and default
  Config::handleEvent implementation
* FrameBufferObject, PixelBufferObject:
** remove setError/getError
** Incompatible return value change from bool to Error for FBO::init,
   FBO::resize, PBO::setup
* Internal error events have an arbitrary number of std::string appended
* add handleEvents() in Config::init and Config::update
Update CHANGES
Move CHANGES file to markdown
Merge branch 'master' into errorevents
CR #247
Merge branch 'master' of https://github.com/Eyescale/Equalizer into errorevents
Use type with boolean operators for Error (#237)
Fix AGL build
Merge branch 'errorevents' of https://github.com/Eyescale/Equalizer into errorevents

Conflicts:
	eq/client/agl/window.cpp
	eq/client/channel.cpp
Fix build
Add originator id to error events (#237)
Discard last todo for #237
Merge branch 'errorevents'