Ensure proper encoding of project name in project aware top menu

'/' in the project name should be encoded as '%2F'. For this the
URL.encodeQueryString method is used now, but then the
setTargetHistoryToken and the selfRedirect methods cannot be used
anymore since they would encode '%2F' as '%252F' and we don't want
double encoding.

Change-Id: I140706e3983a04ab95f565f55edbd7193f36969f
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
Hashtags: use Collections.emptySet() instead of ImmutableSet.of()

Change-Id: I33f7a46ef6c0535ebb2ee034ea8dd3e01b347f61
Move hashtags input class to the extensions API

Change-Id: Icc9cdb8c7894664b3c134618603334991ddb58fa
Add setHashtags method on the change API

Change-Id: I4653857e3266d673f7d04e063da5324f880e5cba
Merge "Hashtags: use Collections.emptySet() instead of ImmutableSet.of()"
Merge "Move hashtags input class to the extensions API"
Merge "Add setHashtags method on the change API"