D-Net

1. Add 'openDoarURL' and 'r3DataURL' properties.
2. #3966: openDoarURL value updated.
3. dataProvider landing page: parse openDoarId or r3DataId and show links according to relevant property.

mailPrefs.component: use 'showSaveResetButtons' variable to show or hide 'save' and 'reset' buttons.

Clean up sitemap, add noindex meta in index.html

1. Add 'lastIndexInformationLink', 'showLastIndexInformationLink', 'widgetLink' properties.
2. depositPublications.component, dataProvider.component, project.component: Use 'statisticsFrameAPIURL' for map and statistics tab instead of raw url.
3. project.component: Use 'widgetLink' for dynamic html in appbox instead of raw url....

Add explore ask question image, add new image for search pages,

Explore: initial css changes for openaire facelift

Use production API urls
Use production urls in main menu and links in home page
Add google verification code
Correct sitemap (also comment orp/software)

1. Add userEmailPreferences page, where user chooses for every openaireId, for which he/she is a manager, IF and HOW OFTEN prefers to receive email notifications.
2. errorCodes.ts & errorMessages.component: Add 'FORBIDDEN' errorCode and appropriate errorMessage.

ignore node_modules file
add missing .angular-cli.json file
add ORPs pages and tabs
Update sitemap
Update properties file

Add landing, search and advanced search page for 'Other Research Products' (using components of library).