* chore(log-viewer): add the ability to use`since` parameter #1942https://github.com/portainer/portainer/issues/1942#issuecomment-430246378
* chore(log-viewer): change lineCount to 100 #1942https://github.com/portainer/portainer/issues/1942#issuecomment-430246378
* fix(log-viewer): js syntax typo for `;` and `'`
forget to lint the code, reported by codeclimate
* fix(log-viewer): use mementjs to format timestamp
1. use moment lib instead of define a function in filter.js(not the right place for this function, removed)
2. set sinceTimestamp init value to `24 hours ago`, as we just need to focus on the relative latest logs after the log-viewer loading, not all the logs(to speedup the process)
3. use moment().unix() to convert the `sinceTimestamp` to local unix timestamp(not utc)
* chore(log-viewer): add the ability to select the datetime for `since`
* chore(log-viewer): add the ability to fetch logs from specific time
pc