Appending suffix to the name of file if the name already exists in dfs.
Nameing modified files in a new way.
Adjusting 'ls' to file versioning. New command 'ls -a'.
Added removing all versions of file.
Added getting the latest version of file.
Merge remote-tracking branch 'origin/feature/6-coherentListing' into feature/9-file_modification

Conflicts:
	src/main/java/client/FileDeleter.java
	src/main/java/client/FileGetter.java
	src/main/java/parser/clicommand/ExecuteCommandVisitor.java
fixes after merge