1. Codes meant to be in hex are specified in decimal.
Consequently characters which don't need escaping are escaped.
2. Special handling (prepend backslash) needed for {, }, and \.
RTF docs generated with those characters cannot be opened in Word.
3. Tab character needs to be escaped as \tab.
RTF docs drop these characters.
While running test suite, found that Writer/RTF/ElementTest was coded
only for Unix line endings, and fails on Windows. Changed so that it
would work on either.
* make FontStyle based on paragraph if it set
* replace tab with spaces
* basedOn not correctly set if FontStyle is based on other FontStyle
* Fix warnings
