update DB to supports GPG encryption
updated handlers and REST to supports GPG settings
updated system reqirements and default to supports GPG encryption
updated notification to supports GPG encrypted mail
implemented GPG encryption and key import
implemented unitTest for GPG encryption
XXX
Merge branch 'master' into feature/gpg-notification

Conflicts:
	globaleaks/handlers/admin.py
	globaleaks/plugins/notification.py
	globaleaks/rest/errors.py
	globaleaks/tests/helpers.py
restored unitTest and python-gnupg module
receiver view updated with AdvSett
GPG armor kept in DB, encryption fully works via mail
Merge branch 'master' into feature/gpg-notification
fixed UT and updated DB with 283 and notification/files
Merge branch 'master' into feature/gpg-notification
first-incomplete implementation of Migration assistence logic
enhanced status checker
completed migration system
changed pip usage in package install procedure
Merge branch 'master' into feature/gpg-notification

Conflicts:
	globaleaks/plugins/notification.py
	globaleaks/rest/errors.py
	globaleaks/tests/helpers.py
fixed unitTest