Fixed issue:#07881: Only survey owner has access to the survey
#8175 fix
In invite admin, hide button the user isn't allow to use
Fixed issue #7919: Uploading duplicate participants erases data
A few minor corrections for pull-request 137.
Fixed issue #7956: No randomisation in Matrix questions with only two answer options
Merge pull request #137 from Grapsus/email_validation

#8175 fix : in admin, check emails before saving them to database
Dev Fixed incorrect usage of empty (pre 5.5 empty only works for
variables).
Fixed issue #8223: Default email texts are not well formatted
Fixed issue #8018: Description and welcome sections of Show Logic File not translated
Dev Fixed some more incorrect usages of empty().
Merge branch 'master' of github.com:LimeSurvey/LimeSurvey
Merge pull request #135 from trougakoss/master

Fixed issue:#07881: Only survey owner has access to the survey
Updated translation: Czech by slansky
Updated translation: German by actxcellence
Updated translation: Norwegian (Bokmål) by pmonstad
Updated translation: Norwegian (Nynorsk) by pmonstad
Updated translation: German (Informal) by actxcellence
Dev: changed a label (consistency with a correction in 2.05)
Updated translation: Catalan by valdomir
Updated translation: Greek by kiolalis
Updated translation: Italian by lfanfoni
Updated translation: Polish by elisa
Updated translation: Slovenian by tejac
Updated translation: Italian (Informal) by lfanfoni
Merge pull request #141 from Grapsus/fix_invite_controls

On token admin page, hide buttons the user isn't allowed to use
Fixed issue #8249: Adv Q-attribs missing in TSV-Export

Dev: List of adv. question attribs need to be listed not only
Dev: in common_helper but also in em_manager_helper.
Dev: Updated the whole list and added a note in common_helper
Fixed issue #8190: Trying to view one or all participants from a certain token table in CPDB gives back HTTP 500 Error
Fixed issue #8235:  Import of old .csv survey file format in Postgresql fails