Zom Android 15.5 beta 2

a2aea78 update to build 1550012
1450f76 small changes and improvements to session handling for OTR
d0b66c7 Merge branch 'N-Pex-join_group_view'
3891efe fix database versoin number
ace2808 Merge branch 'join_group_view' of https://github.com/N-Pex/Zom-Android into N-Pex-join_group_view
c3b63fa updated
a4fb28a Merge branch 'master' of github.com:zom/Zom-Android
210898d Merge pull request #456 from N-Pex/add_friend_group_profile
926e22b Change wording
dd8361e Change wording
267f703 Add friend from group profile view
be2974e Use flags on contact type, implement join group view
b199f35 Merge pull request #446 from licaon-kter/patch-1
cb84f4c update gradle depends
27a7ace persist group encryption toggle UI settings
61220e5 update gradle depends
e6be937 Account settings - proxy port is numeric