Update react panel header when changing angular panel settings 

Add prop key to panelPropsString to avoid a bug when changing another value and the render doesnt trigger

Datasource settings isdefault

add icon

Portal component

Small tooltip css-adjustments and add css for position "bottom-start"…

Create a portal and use it with our popper component (tooltip and popover) to avoid potential overflow-/zindex-bugs

Update css to use the border-radius variable and add a new variable for the popper's distance to its ref

Readme: We should write Node.js the same way in all places in the readme

Develop keep panel settings when switching visualizations

redact value for plugin proxy routes

JS tooling: upgrade to babel 7

Explore: Display duplicate row count as number

Small tooltip css-adjustments and add css for position "bottom-start" used by the panel header corner

Gauge value options

- the pips were hard to see
- make it really clear which rows are duplicates by allocating a column to show number

Explore: Logging query live preview of matches

A logging query has a selector part and a regexp. The regexp matches are highlighted when results return.
This change adds live preview to matches when modifying the regexp in a search field.

- delegate retrieval of match query to datasource
- datasource returns search expressions to be used to highlight a live preview of matches
- logs row now takes preview highlights
- logs row renders preview highlights with dotted line to distinguish from query run matches (solid line)
- fix react-highlight-words version to ensure custom chunk matcher
- custom chunk matcher can now also take incomplete regexps, eg, `(level` without inifinte looping
- perf: debounce of live preview to 500ms
- perf: only top 100 rows get the live preview
- preview is only supported with one query row (multiple rows semantic makes this tricky: regexp for row n should only filter results for query n)