#9: a straightforward way to make text bold  while reading RTF
Task #10: used AttributeController for AttributedStringBuilder logic
Task #11: consider RTF groups for text attributes setting
Task #12: improve control word processing login in string builder
Task #13: added italic processing
Task #14: skip RTF header
Task #15: ignore CR LF chars
Task #6: build a list of RTF files in Document folder
Task #5: load document content in EditorViewController
Task #5: should've check before submitting...
Task #18: ignore \* groups