Uniform insert operations in follow and reblog

Feed cache changes:

• Redefined primary key in FeedCache
• Added block_num column to FeedCache
• FeedCache is now build during initial sync
• Batch insert added to FeedCache following batch insert scheme from other classes

Other changes:

• Added setup_shared_db_access method to class DbAdapterHolder, after initial sync all classes basing on this class will use single db connection to use transaction properly in listen method
• Insert operations in follow and reblog are uniform accross sync mode (initial and live sync)
• Above fixes crash when initial sync is followed by live sync
• Added current system time to logs

added 7 commits

• f73d66a1...b7128908 - 6 commits from branch develop
• a12564a3 - Rebase

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mentioned in merge request !115 (closed)

marked as a Work In Progress

Changed status to WIP since tests shows that some more work is required.

added 1 commit

• 27c9c5dd - Proper FeedCache support and other fixes

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changed the description

unmarked as a Work In Progress

added 1 commit

• 6a24de22 - Fixed order in insert, removed redundant index

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resolved all threads

added 14 commits

• 6a24de22...90359b5c - 13 commits from branch develop
• a58c6ed6 - Rebase to current develop

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added 19 commits

• a58c6ed6...7ebf112e - 18 commits from branch develop
• a933d799 - Merge branch 'dk-uniform-insert-follow-reblog' of...

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added 11 commits

• a933d799...65e39feb - 10 commits from branch develop
• 327133a8 - Rebase to current develop

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added 1 commit

• 74a51665 - Reblog reworked: simplified reblog_op

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added 1 commit

• 54033ef4 - FeedCache reworked

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resolved all threads

added 1 commit

• 12050f3d - Removed not needed join

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added 1 commit

• 6113a736 - text column account replaced with numeric blogger_id in hive_reblogs

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resolved all threads

added 5 commits

• 6113a736...2b1b9a8f - 4 commits from branch develop
• c79d4816 - Rebase to current develop

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mentioned in commit cf3ebd05

merged