Fixed: register commands on editor#pluginsLoaded instead on editor#loaded to have features earlier.
Lists with margins are now fully handled by indentblock. Indentlist handles nesting-only. Code refactoring.
Fixed: enabled indentblock when config.enterMode is ENTER_BR.
Fixed: indentlist canot indent lists with CSS margin when selection isn't in the first list element.
Made enterkey's closing lists independent, removed indent plugin dependency.
Updated doc strings in indent plugin.
Added TAB-based indentation to indentlist and indentblock (entire list). Re-enabled canUndo on content-specific commands by locking snapshots before execution.