Merge pull request #14 from lgromanowski/master

Corrected include name.
Update README.md
ActorFeature as an abstract base class of all features
Merge Attacker and Destrcible features onto Fighter
reffers to #7
Merge branch 'master' of https://github.com/lonski/amarlon
Stackable items feature fix #5
Commands refactor: added method execute, from now on accept methos return
only bool if command can be executed
Generic openable actors, fixes #16
close command update, reffers to #16
Pickable usage and Effects, fixes #8
ActorParser, refers to #19
Overwriting ActorFeatures of actors defined in maps.xml, reffers to #17
Messenger: sending messages to gui, fixes #2
Commands: change input arguments
travis ci script
travis ci script update
travis script update
travis script update
corrected CmdClose filename
travis script updated and cmd close filename corrected
customizable Container content, #21
Merge branch 'master' of https://github.com/lonski/amarlon
exceptions handling in main function