Merge pull request #285 from kruks23/development

Update Spanish Translations
only show muc errors if actually connected
pending leaves and joins for muc
Merge branch 'development' of github.com:siacs/Conversations into development
ignore groupchats messages that are pending leave
fixed #254
simplified presence subscription in contact details
Add Dutch translations.
Merge pull request #289 from jelmer/dutch

Add Dutch translations.
fixed typos reported by @jelmer fixed #288
hide verify snackbar when otr session is ended. fixed npe
disable subscription checkboxes when account is offline
fixed #290
fixed bug where presence requests where sent on display of contact details
switched to direct invites. fixes #284
fixed #267
fixed #292
added hint to explain the contact has read up to this point
back to normal invites. fixed #298
version bump to 0.5-beta and changelog