Start elasticsearch in the foreground by default

Instead of using the '-f' parameter to start elasticsearch in the
foreground, this is now the default modus.

In order to start elasticsearch in the background, the '-d' parameter
can be used.

Closes #4392
Allow to provide parameters not only through -D but as long parameters

All getopt long style parameters are now set as es. properties,

elasticsearch --path.data=/some/path

results in -Des.path.data=/some/path

Closes #4393
fix usage of deprecated netty header method
[DOCS] Removed unused file
Compressed geo-point field data.

This commit allows to trade precision for memory when storing geo points.
This new field data impl accepts a `precision` parameter that controls the
maximum expected error for storing coordinates. This option can be updated on
a live index with the PUT mapping API.

Default precision is 1cm, which requires 8 bytes per geo-point (50% memory
saving compared to using 2 doubles).

Close #4386
Move index health calculations to ClusterIndexHealth so it can be reused.
Fixing typo and grammar
Fail test with timeout and stack dump after 20 min rather than 1h