Script that sets blockedReason and blocks reply rquests

[MrOrz]

Implements part of the blocking mechanism (ReplyRequest only) designed as the 2nd milestone in the User Blocking feature.

• A script, blockUser, is added to set blocked reason (expected to be an URL to an announcement) and changes the user's normal replyRequest status
• Update article's reply request count & last replied at using the remaining normal replyRequests
• The scripts can be executed multiple times in case of error
  • It is tested using production snapshot data; did not encounter any error.

[coveralls]

Coverage decreased (-0.1%) to 86.178% when pulling 6b7d0e2 on block-user-script into b4118e9 on scripts-utils.