Merge pull request #168 from mheinze/master

Jira issue IZPACK-1058
Fix for IZPACK-943

Check the URL for null before creating the ImageIcon. Add a loadIcon()
method to factorize code.
Fix issue IZPACK-1060
Merge pull request #169 from sebastien-christy-neomades/IZPACK-943

Fix for IZPACK-943
Merge pull request #170 from sebastien-christy-neomades/IZPACK-1060

Fix issue IZPACK-1060
[IZPACK-1061] - UserInputPanel: Installer crashes on missing 'set' attribute for RuleInputFields
[IZPACK-1062] - Dynamic variables using checkonce="true" cannot be overwritten by internal variables with the same name
[IZPACK-1059] - AntActionInstallerListener - use graphical InputHandler instead of Ant's DefaultInputHandler in GUI environments
[IZPACK-1059] - AntActionInstallerListener - use graphical InputHandler instead of Ant's DefaultInputHandler in GUI environments
Merge branch 'IZPACK-1059' of github.com:rkrell/izpack into IZPACK-1059

Conflicts:
	izpack-event/src/main/java/com/izforge/izpack/event/AntActionInputHandler.java
Merge pull request #171 from rkrell/IZPACK-1061

[IZPACK-1061] - UserInputPanel: Installer crashes on missing 'set' attribute for RuleInputFields
Merge pull request #172 from rkrell/IZPACK-1062

[IZPACK-1062] - Dynamic variables using checkonce="true" cannot be overwritten by internal variables with the same name
Fix validation of PathInputPanel - chosen path should be validated only on exiting the panel, not on entering the panel
(cherry picked from commit 328825d)
Removed unsused  import
Merge pull request #174 from unb/IZPACK-1015

Fix for IZPACK-1015
Merge pull request #173 from rkrell/IZPACK-1059

[IZPACK-1059] - AntActionInstallerListener - use graphical InputHandler instead of Ant's DefaultInputHandler in GUI environments
[IZPACK-1065] - Inconsistent artifact extension for deploy
Ensure to actually create field for each field specified in the
configuration of the panel.
Checkbox should update its view according to its condition during upon panel viewing panel, and when panel has been revalidated
Combobox should update its view according to its condition during upon panel viewing panel, and when panel has been revalidated