REGISTRAR: new version of tag replacements

- Registrar creates and uses new attribute holding base URL of Perun instance
  for VOs and groups. It's value is used in new tag replacements.

  If attribute is not set (for group) use VOs as backup.
  If attribute not set either (for VO) then use config property "perunUrl".

  If value can't be determined, replace tag by empty space.

- New tags look-like: {tagName-authz} or {tagName} when only attribute value
  is used. If authz is provided, it's appended after attribute value.
  Then, rest of address is calculated from provided context params.
GUI: use new tags in help for registrar notifications
REGISTRAR,GUI: removed support for {validationLinkCustom}

- Removed attribute creation from Registrar.
- Removed support for tag in Registrar notifications.
- Removed tag from help in GUI.
- Fixed help text in GUI.
- Code cleanup.
REGISTRAR: code optimization

- Unified shared code into private methods.
- Public methods moved above private.
- Updated javadoc.
GUI: code optimization

- Fixed "<br/></br>" converted to <p>.
GUI: implemented form and mail copying

- Allow copy registration form or mail definitions in GUI
  from vo/group to vo/group.
Merge pull request #572 from zlamalp/copyForm

GUI: implemented form and mail copying
Merge pull request #571 from zlamalp/registrar

REGISTRAR, GUI: support for new tags in notifications
REGISTRAR: removed usage of vo/group appFormUrl attribute

- Removed usage of appFormUrl attribute for {invitationLink[Authz]} tag.
  Value is taken from perun configuration. For custom URLs now
  can be used new attribute registrarURL and {invitationLink} tag.
REGISTRAR: fixed invitation link replacement
Merge pull request #573 from zlamalp/registrar

REGISTRAR: removed usage of vo/group appFormUrl attribute
Remove keystore/trustore settings from XMLExtSource

 - because settings by System in java change variables at all not only
   on this place
 - now all settings will be at script starting tomcat with perun
   application
Merge pull request #577 from stavamichal/removeSettingFromXmlExtSource

Remove keystore/trustore settings from XMLExtSource