Add mustExist attribute to file fields.
Do not print 'null' during console installation if no label is defined
for a file field. This could easily come up when the user decides to use
    a description tag for their file field instead.
Updated xsd.
Adding skeleton code to display a button through both console and gui
installations
Implementing skeleton to call button actions.
Remove redundant prompt method from the ConsoleField class. This prompt
method is handled by our Console class.
Use reflection to pass InstallData to the button action.
- Ensure to always use a GUIPrompt for GUI button events.
- Ensure to only print success message in console if user has selected
  to press button
Merge branch 'master' into button
Ensure that on window's the program group contains valid syntax
Ensure that install path from GUI target panels contain valid directory
syntax on windows
Ensure target panel through console installation contains valid
directory syntax on windows
Merge branch 'master' into directoryValidation
Add all of fusesource and not just fusource/jansi so that
fusesource/hawtjni packages are included. This should fix the jline
issues on Windows.
Ensure that Ctrl-C still exits the installer during a windows console
installation.
Merge pull request #254 from mtjandra/IZPACK-1090-Fix

[IZPACK-1090] - Windows autocompletion fix
Merge pull request #253 from mtjandra/IZPACK-1148

[IZPACK-1148] - Validate TargetPanel input and ShortcutPanel input on Windows
Merge pull request #250 from mtjandra/IZPACK-1144

[IZPACK-1144] - New button field
Added <tmpdir> element
If administrative privileges are required check that user has
administrative priviliges during console installtion. If user does not
have administrative privileges then inform the user and exit.