Revert "Revert "JC-1449 - Extended size of "value" column in PROPERTIES to store the Forum logo""

This reverts commit 8aefa6b28c1b1aa34d27f723fdea06b2c39ad1c1.
JC-1449 - Migration for 'Extended size of "value" column in PROPERTIES to store the Forum logo' was removed (moved to the Common)
Merge branch 'master' of https://github.com/jtalks-org/jcommune
Changed Common version to 0.51