Merge pull request #17 from Eaglegor/CoreSubsystems

Core subsystems refactorings and bugfixes
Merge pull request #18 from Eaglegor/CoreSubsystems

Very small changes
EngineContext and PluginsManager are stored in the ISceneLoader. XmlSceneLoader interface modified.
Seems that XmlSceneLoader is working now
Find eigen fix
Merge pull request #21 from Eaglegor/XmlSceneLoader

Xml scene loader
Stupid move semantics usage fix
Merge pull request #22 from Eaglegor/CoreSubsystems

Moved initSubsystems from engine start to a separate user/loader call
Merge pull request #23 from Eaglegor/CoreSubsystems

Getter of properties returning boost::optional
Formatting + fixes
Merge branch 'CoreSubsystems' of github.com:Eaglegor/UnknownEngine into PrepareToMergeFormatFiles

Conflicts:
	ComponentSystem/include/MessageSystem/MessagingPoliciesManager.h
	ComponentSystem/src/MessageSystem/MessagingPoliciesManager.cpp
Merge branch 'XmlSceneLoader' of github.com:Eaglegor/UnknownEngine into PrepareToMergeFormatFiles
Merge pull request #24 from Eaglegor/PrepareToMergeFormatFiles

Formatting and some fixes in parsers
Merge branch 'master' of github.com:Eaglegor/UnknownEngine into CoreSubsystems
spaces