Horizon v0.14.1

This release contains several bug fixes:

• Assets stats can cause high CPU usage on stellar-core DB. If this slows down the database it's now possible to turn off this feature by setting DISABLE_ASSET_STATS feature flag. This can be set as environment variable (DISABLE_ASSET_STATS=true) or CLI parameter (--disable-asset-stats=true).
• Sometimes /accounts/{id}/offers returns 500 Internal Server Error response when ledger data is not available yet (for new ledgers) or no longer available (CATCHUP_RECENT deployments). It's possible to set ALLOW_EMPTY_LEDGER_DATA_RESPONSES feature flag as environment variable (ALLOW_EMPTY_LEDGER_DATA_RESPONSES=true) or CLI parameter (--allow-empty-ledger-data-responses=true). With the flag set to true "Offers for Account" endpoint will return null in last_modified_time field when ledger data is not available, instead of 500 Internal Server Error error.

Bug fixes

• Feature flag to disable asset stats (#668).
• Feature flag to allow null ledger data in responses (#672).
• Fix empty memo field in JSON when memo_type is text (#635).
• Improved logging: some bad requests no longer generate ERROR level log entries (#654).
• /friendbot endpoint is available only when FriendbotURL is set in the config.