Add a flag to ignore upvotes of posts by accounts that have been inactive for really long

[pibara]

As described in this HIVE comment, it might be desireable to not vote for posts if the author's account has been inactive for a really long time.

In this issue we want to implement two commandline flags:

• --max-inactive-time : Maximum number of months the account of the post voted for may be inactive (defaults to 12)
• --use-precise-inactive-time: Use a more involved way to determine inactive time of the account.

The standard way to determine the last active time will simply take the latest of the following account parameters:

• last_vote_time : Last time the account voted on a post or comment
• last_post_time : Last time the acount created a post or comment

It is remotely possible that an account has stoped being actively used for posting and voting, but is still for example used as a stake holding account that delegates and receives and claims beneficiary rewards. Or the account is now only used for trading between HIVE and HBD. In the standard check these accounts will be falsely marked as inactive.

When the --use-precise-inactive-time flag is set (default it is not), the bot should do a deeper check if the first check indicates that the account might be inactive. This check will check the most recent 100 actions from the account history. If it finds an action that matches the following, the account will be considered active after all:

• The action timestamp is later than the maximum number of months ago.
• The action is of a type expected by the script.
• The action was done by the account.

Important actions the precise inactive check should check for:

• account_update
• account_update2
• account_witness_vote
• change_recovery_account
• claim-account
• claim_reward_balance
• custom_json
• delegate_vesting_shares
• feed_publish
• fill_order
• fill_vesting_withdraw
• limit_order_create
• transfer
• transfer_to_vesting
• withdraw_vesting