GUI: allow to use custom re-captcha public key

- Read public key for Re-Captcha from perun-web-gui.properties
  stored on server side. This will allow us to use it in
  different Perun instances without need to share are private
  key part.

- If key not present, stop loading appForm gui and display error message.

- Updated PerunError object, so more properties can be set manually.

- Small updates to error reporting widget.

- When response on POST is null (error case) and callback is hidden,
  do not show error report widget.
Merge pull request #244 from zlamalp/captcha

GUI: allow to use custom re-captcha public key
Remove artefacts from facilitiesManagerEntryIntegrationTests

- remove facAdminVo from tests
- create new normal vo instead of facAdminVo in tests
Merge pull request #245 from stavamichal/remove-artefacts-of-facadmins-vo-from-facilities-tests

Remove artefacts from facilitiesManagerEntryIntegrationTests
GUI: fixed typo

- Fixed typo in czech translation for application form.
Merge pull request #247 from zlamalp/typo

GUI: fixed typo
rename and update of module Resources:D:mailingListManagerEmail to resource:D:mailingListManagerEmail
 - Added attribute holder into exception
Core+RPC: added methods getAssigned(Rich)Members
Merge pull request #240 from papperwing/resources

Rename and update of module Resources:D:mailingListManagerEmail to resource:D:mailingListManagerEmail
Merge pull request #249 from jirmauritz/getAssignedMembers

Core+RPC: added methods getAssigned(Rich)Members
Web: add presentation from MetaCentrum seminar