JSON Fixes

What's Changed

• Update .gitignore by @justincslac in #12
• call yajl_gen_free() to prevent memory leaks by @hinxx in #19
• Don't allow both original and JSON commands to be registered simultaneously by @anjohnson in #15
• Add counters for total puts and burst by @henrique-silva in #16
• Patch issues with pvmonitors in EPICS base by @simon-ess in #23
• Add metadata information to json output by @lucmaga in #20
• Fix JSON logger reporting duplicate values despite configuration by @simon-ess in #28
• Add configurable burst filter time by @henrique-silva in #17
• Fix the issue that the log does not stop when config=-1. by @hongran in #33
• Update release notes by @simon-ess in #32

Github Changelog: https://github.com/epics-modules/caPutLog/commits/R4.1

Manual Release Notes: https://github.com/epics-modules/caPutLog/blob/R4.1/docs/releasenotes.rst
Documentation: https://github.com/epics-modules/caPutLog/blob/R4.1/docs/index.rst