[1.5.4] [Refactor] db connection and operations outsourced (PG*, RU*)
Revert "[1.5] called RegisterActivity from Main (PG*, RU*)"

This reverts commit 2049672ea53b5069e0dd24dbb0abfb09882705d0.
[1.5] strings.xml fixed (RU*, PG*)
[1.5]Merge branch 'master' into Register(RU*, PG*)
[1.5] Intent to RegisterActivity added (RU*, PG*)