Allow a displayHidden attribute within the <panel> tags of
UserInputPanel.
- When displayHidden is set to true all fields in this panel will be
  shown regardless if their conditionid is true or false
- If a field's conditionid is false but displayHidden is set to true,
  show the field but disable it
Allow to use displayHidden attribute on individual fields aswell as for entire panels
Give ability to allow disabling any FileInputField object.
Updaing xsd for displayHidden attribute
Ensure TestFieldConfig adheres to updated FieldConfig interface.
Merge branch 'master' into IZPACK-1120

Conflicts:
	izpack-dist/src/main/resources/schema/5.0/izpack-userinput-5.0.xsd
	izpack-panel/src/main/java/com/izforge/izpack/panels/userinput/field/Field.java
Implemented try/catch/final process panel job groups for jira IZPACK-1126.
Added catch and final process panel job attributes to processing schema.
Make linebreaks more clear in console mode
Ensure accurate representation of required pack.
A required pack will always be grey.
If a required pack is a parent and all its children are not selectd, it
will show that it is partially selected in gray.
OnSelect and onDeselect are now active if only its specified condition
is true, or a condition is not defined.
Ensure a required and partially selected pack installs its files
Fix typo of consecutive semi-colons
Update xsd
Merge pull request #226 from mtjandra/IZPACK-1127

[IZPACK-1127]
Merge pull request #219 from mtjandra/IZPACK-1120

[IZPACK-1120]
Added an explicit check for blank inputs so java's File.getAbsolutePath() method
doesn't substitute a blank path for a system-dependent default dir.
Merge branch 'master' of https://github.com/izpack/izpack into IZPACK-1085
Installer keeps a static installerMode variable and getter to check the type of
install (auto, gui, console). Unpacker checks the type of installation when
overwriting files.
Removing redundunt implementation of Panels from AbstractPanels class since PanelViews extends Panels