[IZPACK-1200] Allow default value overrides of dynamic variables from the <variables> section
[IZPACK-1201] Split user input field attribute "set" into "set" and "default"
[IZPACK-1199] Don't refresh a dynamic variable if it has been set by the user on a UserInputPanel
[IZPACK-1201] Split user input field attribute "set" into "set" and "default" - post-fixes for rule input fields:
- Console installer rule fields did not work with their values correctly
- Changed behavior of how 'set' and 'default' values are read -> they must not be preformatted any longer, but there should be used the plain, natural values, which is parsed according to the layout.
- Fixed empty GUI dir/file fields although valid 'set'/'default' value was given in UserInputSpec.xml
Merge pull request #295 from rkrell/IZPACK-1197

IZPACK-1197 - Variable and dynamic variable improvements